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1.  Significance of manipulating tumour hypoxia and radiation dose rate in terms of local tumour response and lung metastatic potential, referring to the response of quiescent cell populations 
The British Journal of Radiology  2010;83(993):776-784.
The purpose of this study was to evaluate the influence of manipulating intratumour oxygenation status and radiation dose rate on local tumour response and lung metastases following radiotherapy, referring to the response of quiescent cell populations within irradiated tumours. B16-BL6 melanoma tumour-bearing C57BL/6 mice were continuously given 5-bromo-2′-deoxyuridine (BrdU) to label all proliferating (P) cells. They received γ-ray irradiation at high dose rate (HDR) or reduced dose rate (RDR) following treatment with the acute hypoxia-releasing agent nicotinamide or local hyperthermia at mild temperatures (MTH). Immediately after the irradiation, cells from some tumours were isolated and incubated with a cytokinesis blocker. The responses of the quiescent (Q) and total (proliferating + Q) cell populations were assessed based on the frequency of micronuclei using immunofluorescence staining for BrdU. In other tumour-bearing mice, 17 days after irradiation, macroscopic lung metastases were enumerated. Following HDR irradiation, nicotinamide and MTH enhanced the sensitivity of the total and Q-cell populations, respectively. The decrease in sensitivity at RDR irradiation compared with HDR irradiation was slightly inhibited by MTH, especially in Q cells. Without γ-ray irradiation, nicotinamide treatment tended to reduce the number of lung metastases. With γ-rays, in combination with nicotinamide or MTH, especially the former, HDR irradiation decreased the number of metastases more remarkably than RDR irradiation. Manipulating both tumour hypoxia and irradiation dose rate have the potential to influence lung metastasis. The combination with the acute hypoxia-releasing agent nicotinamide may be more promising in HDR than RDR irradiation in terms of reducing the number of lung metastases.
doi:10.1259/bjr/57015642
PMCID: PMC3473411  PMID: 20739345
2.  Effects of employing a 10B-carrier and manipulating intratumour hypoxia on local tumour response and lung metastatic potential in boron neutron capture therapy 
The British Journal of Radiology  2012;85(1011):249-258.
Objectives
To evaluate the effects of employing a 10B-carrier and manipulating intratumour hypoxia on local tumour response and lung metastatic potential in boron neutron capture therapy (BNCT) by measuring the response of intratumour quiescent (Q) cells.
Methods
B16-BL6 melanoma tumour-bearing C57BL/6 mice were continuously given 5-bromo-2′-deoxyuridine (BrdU) to label all proliferating (P) cells. The tumours received reactor thermal neutron beam irradiation following the administration of a 10B-carrier [L-para-boronophenylalanine-10B (BPA) or sodium mercaptoundecahydrododecaborate-10B (BSH)] in combination with an acute hypoxia-releasing agent (nicotinamide) or mild temperature hyperthermia (MTH). Immediately after the irradiation, cells from some tumours were isolated and incubated with a cytokinesis blocker. The responses of the Q and total (P+Q) cell populations were assessed based on the frequency of micronuclei using immunofluorescence staining for BrdU. In other tumour-bearing mice, macroscopic lung metastases were enumerated 17 days after irradiation.
Results
BPA-BNCT increased the sensitivity of the total tumour cell population more than BSH-BNCT. However, the sensitivity of Q cells treated with BPA was lower than that of BSH-treated Q cells. With or without a 10B–carrier, MTH enhanced the sensitivity of the Q cell population. Without irradiation, nicotinamide treatment decreased the number of lung metastases. With irradiation, BPA-BNCT, especially in combination with nicotinamide treatment, showed the potential to reduce the number of metastases more than BSH-BNCT.
Conclusion
BSH-BNCT in combination with MTH improves local tumour control, while BPA-BNCT in combination with nicotinamide may reduce the number of lung metastases.
doi:10.1259/bjr/20974899
PMCID: PMC3473983  PMID: 22391496
3.  Effect of bevacizumab combined with boron neutron capture therapy on local tumor response and lung metastasis 
The aim of the present study was to evaluate the effect of bevacizumab on local tumor response and lung metastatic potential during boron neutron capture therapy (BNCT) and in particular, the response of intratumor quiescent (Q) cells. B16-BL6 melanoma tumor-bearing C57BL/6 mice were continuously administered bromodeoxyuridine (BrdU) to label all proliferating (P) tumor cells. The tumors were irradiated with thermal neutron beams following the administration of a 10B-carrier [L-para-boronophenylalanine-10B (BPA) or sodium mercaptoundecahydrododecaborate-10B (BSH)], with or without the administration of bevacizumab. This was further combined with an acute hypoxia-releasing agent (nicotinamide) or mild temperature hyperthermia (MTH, 40°C for 60 min). Immediately following the irradiation, cells from certain tumors were isolated and incubated with a cytokinesis blocker. The responses of the Q cells and the total (P+Q) cell populations were assessed based on the frequency of micronuclei using immunofluorescence staining for BrdU. In other tumor-bearing mice, 17 days following irradiation, lung metastases were enumerated. Three days following bevacizumab administration, the sensitivity of the total tumor cell population following BPA-BNCT had increased more than that following BSH-BNCT. The combination with MTH, but not with nicotinamide, further enhanced total tumor cell population sensitivity. Regardless of the presence of a 10B-carrier, MTH enhanced the sensitivity of the Q cell population. Regardless of irradiation, the administration of bevacizumab, as well as nicotinamide treatment, demonstrated certain potential in reducing the number of lung metastases especially in BPA-BNCT compared with BSH-BNCT. Thus, the current study revealed that BNCT combined with bevacizumab has the potential to sensitize total tumor cells and cause a reduction in the number of lung metastases to a similar level as nicotinamide.
doi:10.3892/etm.2014.1704
PMCID: PMC4061189  PMID: 24944637
bevacizumab; boron neutron capture therapy; 10B-carrier; quiescent cell; nicotinamide; mild temperature hyperthermia
4.  Radiosensitivity of pimonidazole-unlabelled intratumour quiescent cell population to γ-rays, accelerated carbon ion beams and boron neutron capture reaction 
The British Journal of Radiology  2013;86(1021):20120302.
Objective
To detect the radiosensitivity of intratumour quiescent (Q) cells unlabelled with pimonidazole to accelerated carbon ion beams and the boron neutron capture reaction (BNCR).
Methods
EL4 tumour-bearing C57BL/J mice received 5-bromo-29-deoxyuridine (BrdU) continuously to label all intratumour proliferating (P) cells. After the administration of pimonidazole, tumours were irradiated with c-rays, accelerated carbon ion beams or reactor neutron beams with the prior administration of a 10B-carrier. Responses of intratumour Q and total (P+Q) cell populations were assessed based on frequencies of micronucleation and apoptosis using immunofluorescence staining for BrdU. The response of pimonidazole-unlabelled tumour cells was assessed by means of apoptosis frequency using immunofluorescence staining for pimonidazole.
Results
Following c-ray irradiation, the pimonidazole-unlabelled tumour cell fraction showed significantly enhanced radiosensitivity compared with the whole tumour cell fraction, more remarkably in the Q than total cell populations. However, a significantly greater decrease in radiosensitivity in the pimonidazole-unlabelled cell fraction, evaluated using a delayed assay or a decrease in radiation dose rate, was more clearly observed among the Q than total cells. These changes in radiosensitivity were suppressed following carbon ion beam and neutron beam-only irradiaton. In the BNCR, the use of a 10B-carrier, especially L-para-boronophenylalanine-10B, enhanced the sensitivity of the pimonidazole-unlabelled cells more clearly in the Q than total cells.
Conclusion
The radiosensitivity of the pimonidazole-unlabelled cell fraction depends on the quality of radiation delivered and characteristics of the 10B-carrier used in the BNCR.
Advances in knowledge
The pimonidazole-unlabelled subfraction of Q tumour cells may be a critical target in tumour control.
doi:10.1259/bjr.20120302
PMCID: PMC3615400  PMID: 23255546
5.  Adverse effect of mild temperature hyperthermia combined with hexamethylenetetramine compared to its effect combined with tirapazamine in the treatment of solid tumors 
This study aimed to assess the effect on solid tumors of mild temperature hyperthermia (MTH) combined with hexamethylenetetramine (HMTA) or tirapazamine (TPZ). Squamous cell carcinoma (SCC VII) tumor-bearing mice were continuously administered 5-bromo-2′-deoxyuridine (BrdU) to label intratumor proliferating (P) cells. Mice received HMTA or TPZ through intraperitoneal single or subcutaneous continuous administration, with or without MTH (40°C, 60 min), followed or not by γ-ray irradiation or cisplatin treatment. After HMTA or TPZ administration without γ-ray irradiation or cisplatin treatment, immediately after γ-ray irradiation, or 1 h after cisplatin treatment, the response of quiescent (Q) cells was assessed in terms of micronucleus frequency using immunofluorescence staining for BrdU. The response of the total (P + Q) tumor cells was determined based on a comparison with non-BrdU-treated tumors. Without MTH, HMTA and TPZ had a nearly equal radiosensitizing and cisplatin sensitivity-enhancing effect on both total and Q cells. With MTH, radio- and cisplatin-sensitizing effects by HMTA were reduced, particularly in the Q cells. In contrast, the enhancing effects of TPZ were increased, particularly in the Q cells. Continuous administration of HMTA and TPZ resulted in higher radio- and cisplatin-sensitizing effects than intraperitoneal single administration. In terms of tumor cytotoxicity as a whole, including Q cells, the administration of γ-ray irradiation or cisplatin treatment combined with continuous HMTA administration is promising, taking into account the clinical use of HMTA. However, MTH should not be combined with HMTA administration.
doi:10.3892/etm_00000027
PMCID: PMC3490386  PMID: 23136610
mild temperature hyperthermia; hexamethylenetetramine; tirapazamine; quiescent cell; hypoxia
6.  Reduction of hypoxic cells in solid tumours induced by mild hyperthermia: special reference to differences in changes in the hypoxic fraction between total and quiescent cell populations. 
British Journal of Cancer  1997;76(5):588-593.
C3H/He mice bearing SCC VII tumours received 5-bromo-2'-deoxyuridine (BrdU) continuously for 5 days via implanted mini-osmotic pumps in order to label all proliferating (P) cells. The tumours were then heated at 40 degrees C for 60 min. At various time points after heating, tumour-bearing mice were irradiated while alive or after being killed. Immediately after irradiation, the tumours were excised, minced and trypsinized. The tumour cell suspensions obtained were incubated with cytochalasin-B (a cytokinesis blocker), and the micronucleus (MN) frequency in cells without BrdU labelling, which could be regarded as quiescent (Q) cells, was determined using immunofluorescence staining for BrdU. The MN frequency in the total (P+Q) tumour cell population was determined from the irradiated tumours that were not pretreated with BrdU. The MN frequency of BrdU unlabelled cells was then used to calculate the surviving fraction of the unlabelled cells from the regression line for the relationship between the MN frequency and the surviving fraction of total (P+Q) tumour cells. In general, Q cells contained a greater hypoxic fraction (HF) than the total tumour cell population. Mild heating decreased the HF of Q cells more markedly than in the total cell population, and the minimum values of HFs of both total and Q cell populations were obtained 6 h after heating. Two days after heating, the HF of total tumour cells returned to almost that of unheated tumours. In contrast, the HF of Q cells did not return to the HF level of unheated tumours until 1 week after heating. It was thought that irradiation within 12 h after mild heating might be a potentially promising therapeutic modality for controlling radioresistant Q tumour cells.
PMCID: PMC2228014  PMID: 9303356
7.  A dual hypoxic marker technique for measuring oxygenation change within individual tumors. 
British Journal of Cancer  1998;78(2):163-169.
Rodent tumour models have been the 'workhorse' for tumour oxygenation research and for investigating radiobiological hypoxic fraction. Because of the intertumour heterogeneity of blood flow and related parameters, most studies have pooled information derived from several different tumours to establish the statistical significance of specific measurements. But it is the oxygenation status of and its modulation in individual tumours that has important prognostic significance. In that regard, the bioreducible hypoxic marker technique was tested for its potential to quantify oxygenation changes within individual tumours. Beta-D-iodinated azomycin galactoside (IAZG) and beta-D-iodinated azomycin xylopyranoside (IAZXP) were each radiolabelled with Iodine-125 and iodine-131 for measurements of animal tumour oxygenation. The tumour-blood (T/B) ratio of marker radioactivity in mice after the renal excretion of unbound marker (at 3 h and longer times) had been shown to be proportional to radiobiological hypoxic fraction. When markers labelled with both radioisotopes were administered simultaneously to EMT-6 tumour-bearing scid mice, T/B ratios were found to vary by up to 300% between different tumours, with an average intratumour variation of only approximately 4%. When the markers were administered 2.5-3.0 h apart, changes in T/B ratios of 8-25% were observed in 10 out of 28 (36%) tumours. Changes to both higher and lower hypoxic fraction were observed, suggestive of acute or cycling hypoxia. When 0.8 mg g(-1) nicotinamide plus carbogen was administered to increase tumour oxygenation, reductions in T/B ratios (mean deltaT/B approximately 38%) were observed in all tumours. Similar results were obtained with Dunning rat prostate carcinomas growing in Fischer x Copenhagen rats whose T/B ratios of IAZG and radiobiological hypoxic fractions are significantly lower. These studies suggest that fluctuating hypoxia can account for at least 25% of the total hypoxic fraction in some tumours and that correlations between bioreducible marker avidity and related tumour properties will be optimal when the independent assays are performed over the same time period. This dual hypoxic marker technique should prove useful for investigating both spontaneous and induced oxygenation changes within individual rodent tumours.
PMCID: PMC2062896  PMID: 9683288
8.  Cisplatin plus paclitaxel and maintenance of bevacizumab on tumour progression, dissemination, and survival of ovarian carcinoma xenograft models 
British Journal of Cancer  2012;107(2):360-369.
Background:
Bevacizumab is being incorporated as first-line therapy with standard-of-care chemotherapy on epithelial ovarian carcinoma (EOC). We investigated bevacizumab combined with chemotherapy on tumour progression and mouse survival in EOC xenograft models.
Methods:
Bevacizumab was administered concomitantly with cisplatin plus paclitaxel (DDP+PTX), continued after induction (maintenance) or started after chemotherapy. The effect on tumour progression was monitored by bioluminescence imaging (BLI) (1A9-luc xenograft). Tumour dissemination into the peritoneal organs and ascites formation (HOC22 xenograft) was evaluated by histological analysis at the end of treatment (interim) and at euthanasia (survival). The effects on overall survival (OS) were investigated in both EOC models.
Results:
Bevacizumab with PTX+DDP delayed tumour progression in mice bearing EOC xenografts. OS was significantly extended, with complete responses, by bevacizumab continued after stopping chemotherapy in the HOC22 xenograft. Bevacizumab alone inhibited ascites formation, with only limited effect on tumour burden, but combined with PTX+DDP reduced ascites and metastases. Bevacizumab started after induction with PTX+DDP and maintained was equally effective on tumour progression and survival on 1A9-luc xenograft.
Conclusion:
Bevacizumab combined with chemotherapy not only affected tumour progression, but when administered as maintenance regimen significantly prolonged survival, reducing ascites, and tumour dissemination. We believe our findings are consistent with the clinical results and shed light on the potential effects of this kind of treatment on tumour progression.
doi:10.1038/bjc.2012.261
PMCID: PMC3394985  PMID: 22713663
cisplatin; paclitaxel; bevacizumab; ovarian carcinoma; metastasis
9.  Wortmannin efficiently suppresses the recovery from radiation-induced damage in pimonidazole-unlabeled quiescent tumor cell population 
Journal of Radiation Research  2012;54(2):221-229.
Labeling of proliferating (P) cells in mice bearing EL4 tumors was achieved by continuous administration of 5-bromo-2′-deoxyuridine (BrdU). Tumors were irradiated with γ-rays at 1 h after pimonidazole administration followed by caffeine or wortmannin treatment. Twenty-four hours later, assessment of the responses of quiescent (Q) and total (= P + Q) cell populations were based on the frequencies of micronucleation and apoptosis using immunofluorescence staining for BrdU. The response of the pimonidazole-unlabeled tumor cell fractions was assessed by means of apoptosis frequency using immunofluorescence staining for pimonidazole. The pimonidazole-unlabeled cell fraction showed significantly enhanced radio-sensitivity compared with the whole cell fraction more remarkably in Q cells than total cells. However, a significantly greater decrease in radio-sensitivity in the pimonidazole-unlabeled than the whole cell fraction, evaluated using an assay performed 24 hours after irradiation, was more clearly observed in Q cells than total cells. In both the pimonidazole-unlabeled and the whole cell fractions, wortmannin efficiently suppressed the reduction in sensitivity due to delayed assay. Wortmannin combined with γ-ray irradiation is useful for suppressing the recovery from radiation-induced damage especially in the pimonidazole-unlabeled cell fraction within the total and Q tumor cell populations.
doi:10.1093/jrr/rrs094
PMCID: PMC3589932  PMID: 23097299
Quiescent cell; recovery from radiation-induced damage; pimonidazole; wortmannin; caffeine
10.  Efficacy and Safety of Bevacizumab in Active Brain Metastases from Non-Small Cell Lung Cancer 
Journal of neuro-oncology  2010;100(3):443-447.
Background
Bevacizumab is effective for the treatment of non-small cell lung cancer (NSCLC). Ongoing trials are exploring the safety of bevacizumab in patients with inactive, previously treated brain metastases. However, bevacizumab safety and efficacy in the treatment of active brain metastases is unknown. Bevacizumab received accelerated FDA approval for progressive glioblastoma, a primary brain tumor, because of high response rates and low incidence of intracranial hemorrhage.
Methods
We retrospectively identified patients treated with bevacizumab for active (treatment naïve or progressive) central nervous system (CNS) metastases from NSCLC. MRI scans performed at least 6 weeks after initiating bevacizumab were assessed for response.
Results
There were six patients, four women and two men with a median age of 60 years (range 59–77) at initiation of bevacizumab. Five patients had progressive CNS metastases despite prior treatment including surgery, radiotherapy, and/or chemotherapy; one patient had treatment-naïve brain metastases. Two patients had leptomeningeal metastases, isolated or coexistent with parenchymal brain metastases in one patient each. Bevacizumab was administered alone to one patient and in combination with various cytotoxic chemotherapies in the others. Toxicity included an asymptomatic (Grade 1) intra-tumoral hemorrhage which occurred in one of three patients receiving concurrent anticoagulation with bevacizumab. There was no recurrent CNS bleeding in two patients with a prior history of such hemorrhage. Best response (RECIST) was partial in two, stable disease in three, and progression in one. Median progression-free survival (PFS) was 4.7 months and median overall survival (OS) was 14.1 months following initiation of bevacizumab. Clinical benefit was also observed in the form of improved symptoms and reduced corticosteroid requirements.
Conclusions
Bevacizumab should be used with caution in patients with active CNS metastases pending additional safety data. This series suggests bevacizumab may be safe and effective for progressive brain metastases from NSCLC and deserves further study.
doi:10.1007/s11060-010-0200-2
PMCID: PMC3246379  PMID: 20440540
Non-small cell lung cancer; brain metastases; bevacizumab; radiotherapy; chemotherapy
11.  Carbonic anhydrase IX promotes tumour growth and necrosis in vivo and inhibition enhances anti-VEGF therapy 
Clinical Cancer Research  2012;18(11):3100-3111.
Purpose
Bevacizumab, an anti-VEGFA antibody, inhibits the developing vasculature of tumours, but resistance is common. Antiangiogenic therapy induces hypoxia and we observed increased expression of hypoxia-regulated genes, including carbonic anhydrase IX (CAIX), in response to Bevacizumab treatment in xenografts. CAIX expression correlates with poor prognosis in most tumour types and with worse outcome in Bevacizumab-treated metastatic colorectal cancer patients, malignant astrocytoma and recurrent malignant glioma.
Experimental Design
We knocked-down CAIX expression by shRNA in a colon cancer (HT29) and a glioblastoma (U87) cell line which have high hypoxic-induction of CAIX, and over-expressed CAIX in HCT116 cells which has low CAIX. We investigated the effect on growth rate in 3D culture and in vivo, and examined the effect of CAIX knockdown in combination with Bevacizumab.
Results
CAIX expression was associated with increased growth rate in spheroids and in vivo. Surprisingly, CAIX expression was associated with increased necrosis and apoptosis in vivo and in vitro. We found that acidity inhibits CAIX activity over the pH range found in tumours (pK=6.84), and this may be the mechanism whereby excess acid self-limits the build-up of extracellular acid. Expression of another hypoxia inducible CA isoform, CAXII, was upregulated in 3D but not 2D culture in response to CAIX knockdown. CAIX knockdown enhanced the effect of Bevacizumab treatment, reducing tumour growth rate in vivo.
Conclusion
This work provides evidence that inhibition of the hypoxic adaptation to anti-angiogenic therapy enhances Bevacizumab treatment and highlights the value of developing small molecules or antibodies which inhibit CAIX for combination therapy.
doi:10.1158/1078-0432.CCR-11-1877
PMCID: PMC3367109  PMID: 22498007
Carbonic anhydrase IX; Bevacizumab; Hypoxia; Carbonic anhydrase XII; pH homeostasis
12.  Carbonic anhydrase IX promotes tumour growth and necrosis in vivo and inhibition enhances anti-VEGF therapy 
Purpose
Bevacizumab, an anti-VEGFA antibody, inhibits the developing vasculature of tumours, but resistance is common. Antiangiogenic therapy induces hypoxia and we observed increased expression of hypoxia-regulated genes, including carbonic anhydrase IX (CAIX), in response to Bevacizumab treatment in xenografts. CAIX expression correlates with poor prognosis in most tumour types and with worse outcome in Bevacizumab-treated metastatic colorectal cancer patients, malignant astrocytoma and recurrent malignant glioma.
Experimental Design
We knocked-down CAIX expression by shRNA in a colon cancer (HT29) and a glioblastoma (U87) cell line which have high hypoxic-induction of CAIX, and over-expressed CAIX in HCT116 cells which has low CAIX. We investigated the effect on growth rate in 3D culture and in vivo, and examined the effect of CAIX knockdown in combination with Bevacizumab.
Results
CAIX expression was associated with increased growth rate in spheroids and in vivo. Surprisingly, CAIX expression was associated with increased necrosis and apoptosis in vivo and in vitro. We found that acidity inhibits CAIX activity over the pH range found in tumours (pK=6.84), and this may be the mechanism whereby excess acid self-limits the build-up of extracellular acid. Expression of another hypoxia inducible CA isoform, CAXII, was upregulated in 3D but not 2D culture in response to CAIX knockdown. CAIX knockdown enhanced the effect of Bevacizumab treatment, reducing tumour growth rate in vivo.
Conclusion
This work provides evidence that inhibition of the hypoxic adaptation to anti-angiogenic therapy enhances Bevacizumab treatment and highlights the value of developing small molecules or antibodies which inhibit CAIX for combination therapy.
doi:10.1158/1078-0432.CCR-11-1877
PMCID: PMC3367109  PMID: 22498007
Carbonic anhydrase IX; Bevacizumab; Hypoxia; Carbonic anhydrase XII; pH homeostasis
13.  Combined effects of bevacizumab with erlotinib and irradiation: a preclinical study on a head and neck cancer orthotopic model 
British Journal of Cancer  2008;99(1):93-99.
Clinical benefit has been demonstrated in patients with head and neck tumours receiving an anti-epidermal growth factor receptor (EGFR) agent in combination with radiotherapy (RT). Recent preclinical and clinical studies suggest beneficial effects from combining anti-angiogenic drugs with RT. To investigate the effect of combining these approaches, we evaluated in vivo the anti-tumour efficacy of the anti-angiogenic compound bevacizumab, a highly specific monoclonal antibody directed against the vascular endothelial growth factor (VEGF), erlotinib, an EGFR tyrosine kinase inhibitor, and irradiation given alone and in combination. Investigations were performed using a VEGF-secreting human head and neck tumour cell line, CAL33, with a high EGFR content, injected as orthotopic xenografts into the mouth floor of nude mice. Three days after tumour cell injection, bevacizumab (5 mg kg−1, 5 days a week, i.p.), erlotinib (100 mg kg−1, 5 days a week, orally) and irradiation (6 Gy, 3 days a week) were administered alone and in combination for 10 days. As compared with the control, concomitant administration of drugs produced a marked and significant supra-additive decrease in tumour mass; the addition of irradiation almost completely abolished tumour growth. The drug association markedly reduced the number of metastatic nodes and the triple combination significantly reduced the total number of pathologically positive lymph nodes as compared with controls. The RT-induced proliferation, reflected by Ki67 labelling, was reduced to control level with the triple combination. Radiotherapy induced a strong and very significant increase in tumour angiogenesis, which was no longer observed when combined with erlotinib and bevacizumab. The efficacy of the combination of bevacizumab+erlotinib and RT may be of clinical importance in the management of head and neck cancer patients.
doi:10.1038/sj.bjc.6604429
PMCID: PMC2453013  PMID: 18577994
bevacizumab; erlotinib; irradiation; head and neck cancer; orthotopic
14.  Vascular endothelial growth factor expression and inhibition in uveal melanoma cell lines 
ecancermedicalscience  2013;7:336.
Background:
Uveal melanoma (UM) is a disease that affects approximately five people per million in the United States. This disease metastasises predominantly to the liver, and treatment options following the clinical detection of these sequelae are limited. Vascular endothelial growth factor-A (VEGF-A) is the primary activator of tumour angiogenesis and functions by binding to VEGF-Receptor 2 (VEGF-R2) and is often required for tumour growth beyond 2–3 mm. The purpose of this study was to investigate the expression of VEGF-A and the primary VEGF-R2 in three UM cell lines. Furthermore, we investigated the effects of VEGF-A inhibition on receptor activation and production of other cytokines. Finally, the effects of VEGF-A inhibition on the proliferation, migration, and invasion in the cell lines were ascertained.
Materials:
Three UM cell lines (92.1, OCM-1, and UW-1) were incubated with and without the addition of 100 μg/mL of bevacizumab. VEGF-A expression under both conditions was determined by sandwich enzyme-linked immunosorbent assay (ELISA), and phosphorylated VEGF-R2 expression was determined using western blot. The effects of VEGF-A inhibition on 20 cytokines (IL-1a, IL-2, IL-5, IL-8, IL-12p70, GM-CSF, IFNy, CCL3, MMP-9, TNF-a, IL-1b, IL-4, IL-6, IL-10, IL-13, GRO, MCP-1, MIP-1b, and RANTES) were determined using a multiplex sandwich ELISA. Proliferation rates before and after treatment were evaluated via sulforhodamine B assay, and migration and invasion assays implementing the Boyden chamber technique, the latter with artificial extracellular matrix, were used to assess their respective abilities. The Student’s t-test was used to compare changes in cytokine expression following VEGF-A inhibition. Analysis of variance was used to compare changes in the functional abilities of three uveal melanoma cell lines following VEGF-A inhibition. A P-value < 0.05 was considered statistically significant.
Results:
All three cell lines produced copious amounts of VEGF-A in culture (92.1, 11785.5 ± 231.8 pg/μL; OCM-1, 4608.0 ± 324.0 pg/μL; UW-1, 8309.3 ± 634.5 pg/μL), which was reduced to undetectable levels following the administration of bevacizumab (P< 0.05). Similarly, detectable phosphorylated VEGF-R2 was present in all cells, which was reduced significantly in all cell lines following bevacizumab treatment (107525.2 ± 8602.0 versus 1024.5 ± 98.2, 46587.3 ± 4192.9 versus 12821.1 ± 1666.7, and 60394.3 ± 4026.4 versus 6908.2 ± 607.2; 92.1, OCM-1, and UW-1, respectively; P< 0.05). Of the cytokines investigated, only MMP-9 and CCL3 were ubiquitously altered across all three cell lines following bevacizumab treatment; they were upregulated (CCL3: 1072.50 ± 18.77 pg/mL versus 1281.00 ± 72.34 pg/mL; 22.5 ± 7.85 pg/mL versus 62.00 ± 9.16 pg/mL; 20.33 ± 6.35 pg/mL versus 35.00 ± 6.22 pg/mL; control versus bevacizumab; MMP-9: 25.50 ± 5.47 pg/mL versus 88.25 ± 13.38 pg/mL; 19.75 ± 4.14 pg/mL versus 45.25 ± 8.36 pg/mL; 3.25 ± 1.09 pg/mL versus 19.25 ± 3.77 pg/mL; control versus bevacizumab; 92.1, OCM-1, and UW-1, respectively; P< 0.05). Bevacizumab significantly reduced the proliferation of one cell line (92.1: 0.405 ± 0.012 versus 0.509 ± 0.033; bevacizumab versus control; values OD; P< 0.05), the migration of two cell lines (92.1: 0.071 ± 0.003 versus 0.115 ± 0.003; OCM-1: 0.049 ± 0.005 versus 0.117 ± 0.014; bevacizumab versus control; values OD; P< 0.05), and did not significantly affect invasion.
Conclusion:
Despite the significant reduction in phosphorylated VEGF-R2 levels, bevacizumab did not have a dramatic impact on the functional abilities of the three UM cell lines studied. Our results indicate that compensatory mechanisms, such as the upregulation of MMP-9 and CCL-3, following bevacizumab administration may mitigate its effects on these abilities.
doi:10.3332/ecancer.2013.336
PMCID: PMC3729237  PMID: 23914254
uveal melanoma; VEGF-A; invasion; migration; proliferation; bevacizumab
15.  Bevacizumab and intraocular tumors: an intriguing paradox 
Molecular Vision  2012;18:2454-2467.
Purpose
Bevacizumab, a humanized monoclonal antibody to vascular endothelial growth factor-A (VEGF-A), was originally developed as an anti-tumor treatment. In ocular oncology, it is being used to treat macular edema due to radiation retinopathy, but it may also be useful for the treatment of primary uveal melanoma (UM) or its metastases. We determined the effect of bevacizumab on the growth of B16F10 cells inside the eye and on B16F10 and UM cells cultured in vitro.
Methods
B16F10 melanoma cells were placed into the anterior chamber of the eye of C57Bl/6 mice and tumor growth was monitored after injection of different doses of bevacizumab or mock injection. In addition, the effect of bevacizumab on in vitro growth of B16F10 and human UM cells and on the expression of VEGF-A, GLUT-1, and HIF-1α was evaluated.
Results
Following intraocular injection of bevacizumab into murine B16 tumor-containing eyes, an acceleration of tumor growth was observed, with the occurrence of anterior chamber hemorrhages. Bevacizumab did not affect proliferation of B16F10 cells in vitro, while it inhibited UM cell proliferation. Expression analysis demonstrated that addition of bevacizumab under hypoxic conditions induced VEGF-A, GLUT-1 and HIF-1α in B16F10 cells as well as in UM cell lines and two of four primary UM tumor cultures.
Conclusions
In contrast with expectations, intraocular injection of bevacizumab stimulated B16F10 melanoma growth in murine eyes. In vitro exposure of B16 and human UM cells to bevacizumab led to paradoxical VEGF-A upregulation. The use of VEGF inhibitors for treatment of macular edema (due to radiation retinopathy) after irradiation of UM should be considered carefully, because of the possible adverse effects on residual UM cells.
PMCID: PMC3472924  PMID: 23077404
16.  Administration of anti-vascular endothelial growth factor antibody following hepatectomy does not inhibit remnant liver regeneration or growth of remnant metastases 
In addition to the use of chemotherapeutic agents for the prevention of multiple liver metastases from colorectal cancer, the anti-vascular endothelial growth factor (VEGF) antibody, bevacizumab, is often used, and its effectiveness has been established. By contrast, it has been reported that the use of bevacizumab prior to or following surgery delays wound healing or liver regeneration. In this study, we investigated whether the administration of bevacizumab following hepatectomy inhibits remnant liver regeneration or the growth of remnant metastases. Mice were partially hepatectomized (31% of the liver was removed), transplanted with the murine colorectal cancer cell line, CT26, in the remnant lobe, and intraperitoneally injected with bevacizumab (4 mg/kg) for a total of 6 times. Serum VEGF levels were measured on day 1 following surgery, and each lobe of the liver was weighed on day 14. Serum VEGF levels in non-hepatectomized, tumor-bearing mice exceeded those in their non-tumor-bearing counterparts; however, the administration of bevacizumab did not reduce the serum VEGF levels. The volume of the liver lobe of the hepatectomized, CT26-transplanted and non-CT26-transplanted mice was 1,349.6 and 735.5 mg, respectively, indicating rapid growth of the CT26 transplant (p=0.023). The volume of the CT26-transplanted lobe of the bevacizumab-administered mice was 1,379.0 mg, which was not significantly different from that (1,349.6 mg) of the non-bevacizumab-administered mice. The volume of the remnant lobe of the bevacizumab-administered mice was 1,051.0 mg, which did not significantly differ from that (957.3 mg) of the non-bevacizumab-administered mice. The administration of bevacizumab following hepatectomy did not delay remnant liver regeneration, and did not suppress the growth of metastases in the remnant lobes or remnant liver regeneration.
doi:10.3892/etm.2011.409
PMCID: PMC3438680  PMID: 22969894
vascular endothelial growth factor; antibody; hepatectomy; regeneration
17.  Nicotinamide, Fluosol DA and Carbogen: a strategy to reoxygenate acutely and chronically hypoxic cells in vivo. 
British Journal of Cancer  1991;63(1):109-113.
The effect of Nicotinamide and/or treatment with Fluosol DA and Carbogen breathing on the radiation response of 500-750 mg SCCVII and KHT tumours has been evaluated. Pretreatment with Fluosol DA/Carbogen or Nicotinamide resulted in relatively modest enhancements of radiation damage with enhancement factors of 1.1 and 1.3 being observed using an in vivo/in vitro clonogenic end-point. A combination of Nicotinamide and Fluosol DA/Carbogen resulted in a larger enhancement factor of 1.6 over the radiation dose ranges studied. These modification factors reflect a value close to that expected for a fully aerobic response in this survival range. Growth delay studies in the SCCVII tumour provided similar results. Using a recently developed fluorescence activated cell sorting technique, which utilizes the in vivo pharmacokinetic and DNA binding properties of the bisbenzamide stain Hoechst 33342, the effect of Nicotinamide and/or Fluosol DA/Carbogen schedules on the occurrence of acute hypoxia was assessed. The results clearly show that Nicotinamide significantly reduces the amount of 'acute hypoxia', but has a lesser effect on 'chronic' hypoxic cells. However, combinations of Nicotinamide and Fluosol DA/Carbogen significantly increase the response of both 'acutely' and 'chronically hypoxic' cells. The results provide evidence that a combination of Nicotinamide and Fluosol DA/Carbogen can provide an effective way of reoxygenating both acutely and chronically hypoxic cells.
PMCID: PMC1971634  PMID: 1846549
18.  Efficacy of bevacizumab plus erlotinib versus erlotinib alone in advanced non-small-cell lung cancer after failure of standard first-line chemotherapy (BeTa): a double-blind, placebo-controlled, phase 3 trial 
Lancet  2011;377(9780):1846-1854.
Summary
Background
Bevacizumab and erlotinib target different tumour growth pathways with little overlap in their toxic-effect profiles. On the basis of promising results from a phase 1/2 trial assessing safety and activity of erlotinib plus bevacizumab for recurrent or refractory non-small-cell lung cancer (NSCLC), we aimed to assess efficacy and safety of this combination in a phase 3 trial.
Methods
In our double-blind, placebo-controlled, randomised phase 3 trial (BeTa), we enrolled patients with recurrent or refractory NSCLC who presented to 177 study sites in 12 countries after failure of first-line treatment. Patients were randomly allocated in a one-to-one ratio to receive erlotinib plus bevacizumab (bevacizumab group) or erlotinib plus placebo (control group) according to a computer-generated randomisation sequence by use of an interactive voice response system. The primary endpoint was overall survival in all enrolled patients. Patients, study staff, and investigators were masked to treatment assignment. We assessed safety by calculation of incidence of adverse events and tissue was collected for biomarker analyses. This trial is registered with ClinicalTrials.gov, number NCT00130728.
Findings
Overall survival did not differ between 317 controls and 319 patients in the bevacizumab group (hazard ratio [HR] 0·97, 95% CI 0·80–1·18, p=0·7583). Median overall survival was 9·3 months (IQR 4·1–21·6) for patients in the bevacizumab group compared with 9·2 months (3·8–20·2) for controls. Progression-free survival seemed to be longer in the bevacizumab group (3·4 months [1·4–8·4]) than in the control group (1·7 months [1·3–4·1]; HR 0·62, 95% CI 0·52–0·75) and objective response rate suggested some clinical activity of bevacizumab and erlotinib. However, these secondary endpoint differences could not be defined as significant because the study prespecified that the primary endpoint had to be significant before testing of secondary endpoints could be done, to control type I error rate. In the bevacizumab group, 130 (42%) of 313 patients with safety data had a serious adverse event, compared with 114 (36%) controls. There were 20 (6%) grade 5 adverse events, including two arterial thromboembolic events, in the bevacizumab group, and 14 (4%) in the control group.
Interpretation
Addition of bevacizumab to erlotinib does not improve survival in patients with recurrent or refractory NSCLC.
Funding
Genentech.
doi:10.1016/S0140-6736(11)60545-X
PMCID: PMC4134127  PMID: 21621716
19.  Intracranial hemorrhage in patients treated with bevacizumab: Report of two cases 
Treatment with bevacizumab, an antiangiogenic agent, in patients with metastatic or unresectable colorectal cancer was approved less than 4 years ago in Japan. Bevacizumab improves the survival of patients with metastatic colorectal cancer; however, it may lead to complications such as bleeding, which are sometimes fatal. Bevacizumab should be administered only after careful consideration because the potential risks of therapy outweigh its benefits. Therefore, pharmaceutical companies do not recommend bevacizumab therapy for patients with brain metastases. While some reports support the cautious use of bevacizumab, others report that it is not always necessary to prohibit its use in patients with metastases to the central nervous system (CNS), including the brain. Thus, bevacizumab therapy in colorectal cancer patients with brain metastases is controversial, and it is unclear whether brain metastases are a risk factor for intracranial hemorrhage during anti-vascular endothelial growth factor (VEGF) therapy. We report a 64-year-old man and a 65-year-old man with recurrent colorectal cancer without brain metastases; these patients developed multifocal and solitary intracranial hemorrhage, respectively, after the administration of bevacizumab. Our findings suggest that intracranial hemorrhage can occur even if the patient does not have brain metastases prior to bevacizumab treatment and also suggest that brain metastases are not a risk factor for intracranial hemorrhage with bevacizumab treatment. These findings also question the necessity of excluding patients with brain metastases from clinical trials on anti-VEGF therapy.
doi:10.3748/wjg.v17.i39.4440
PMCID: PMC3218160  PMID: 22110272
Anti-vascular endothelial growth factor therapy; Bevacizumab; Central nervous system; Colorectal cancer; Intracranial hemorrhage
20.  Local hypoxia is produced at sites of intratumour injection 
British Journal of Cancer  2002;86(3):429-435.
Intratumour injection, commonly used for gene or drug delivery but also associated with needle biopsy or insertion of invasive measuring devices, may damage tumour microvessels. To examine this possibility, SCCVII tumours grown subcutaneously in C3H mice were injected with a 26 gauge needle containing 0.1 ml of the fluorescent dye Hoechst 33342 to label cells lining the track of the needle. Hoechst-labelled cells sorted from these tumours were more sensitive to killing by hypoxic cell cytotoxins (tirapazamine, RSU-1069) and less sensitive to damage by ionizing radiation. Hoechst-labelled cells also bound the hypoxia marker pimonidazole when given by i.p. injection. Intratumour injection transiently increased hypoxia from 18 to 70% in the tumour cells adjacent to the track of the needle. The half-time for return to pre-treatment oxygenation was about 30 min; oxygenation of tumour cells along the track had recovered by 20 h after intratumour injection. This effect could have significant implications for intratumour injection of drugs, cytokines or vectors that are affected by the oxygenation status of the tumour cells as well as potential effects on biodistribution via local microvasculature.
British Journal of Cancer (2002) 86, 429–435. DOI: 10.1038/sj/bjc/6600059 www.bjcancer.com
© 2002 The Cancer Research Campaign
doi:10.1038/sj.bjc.6600059
PMCID: PMC2375199  PMID: 11875711
tumour hypoxia; pimonidazole; intratumour injection
21.  Docetaxel-carboplatin in combination with erlotinib and/or bevacizumab in patients with non-small cell lung cancer 
OncoTargets and therapy  2013;6:125-134.
Background
Bevacizumab and erlotinib have been demonstrated to prolong overall survival in patients with non-squamous non-small cell lung cancer (NSCLC). We designed a four-arm Phase III trial to evaluate the efficacy and toxicity of the combination of docetaxel, carboplatin, bevacizumab, and erlotinib in the first-line treatment of patients with NSCLC.
Methods
A total of 229 patients with stage IIIb/IV non-squamous NSCLC were treated with two cycles of carboplatin (area under the concentration-time curve 5.5) and docetaxel 100 mg/m2 as chemotherapy. After completion of two treatment cycles, patients were evaluated for response and divided into four groups: 61/229 continued with four more cycles of chemotherapy (control group), 52/229 received chemotherapy plus erlotinib 150 mg daily, 56/229 received chemotherapy plus bevacizumab 7.5 mg/kg, and 60/229 were treated with the combination of chemotherapy, erlotinib, and bevacizumab until disease progression. The primary endpoint was overall survival.
Results
Over 4 years of follow-up, there was no statistically significant difference in survival and time to progression between the four treatment groups. After two cycles of chemotherapy, responders and nonresponders were divided according to their response in order to examine the role of initial response as an independent factor in survival and response when a biological agent is combined with chemotherapy. Nonresponders, who received additional therapy with bevacizumab or combination therapy, had a survival benefit [657 days (95% confidence interval 349–970) and 681 days (95% confidence interval 315–912), respectively], which was statistically significant compared with continuation of cytotoxic chemotherapy (P < 0.001). The combination therapy had a safety profile comparable with that of bevacizumab and erlotinib taken individually.
Conclusion
Administration of bevacizumab and erlotinib in combination with first-line chemotherapy, followed by bevacizumab and erlotinib monotherapy as maintenance, showed promising results in patients with NSCLC, with reduced toxicity as compared with chemotherapy alone, but did not translate into longer overall survival.
doi:10.2147/OTT.S42245
PMCID: PMC3589083  PMID: 23467839
vascular endothelial growth factor; epidermal growth factor receptor; erlotinib; bevacizumab; non-small cell lung cancer
22.  The dependency of compound biological effectiveness factors on the type and the concentration of administered neutron capture agents in boron neutron capture therapy 
SpringerPlus  2014;3:128.
Purpose
To examine the effect of the type and the concentration of neutron capture agents on the values of compound biological effectiveness (CBE) in boron neutron capture therapy.
Methods and materials
After the subcutaneous administration of a 10B-carrier, boronophenylalanine-10B (BPA) or sodium mercaptododecaborate-10B (BSH), at 3 separate concentrations, the 10B concentrations in tumors were measured by γ-ray spectrometry. SCC VII tumor-bearing C3H/He mice received 5-bromo-2′-deoxyuridine (BrdU) continuously to label all intratumor proliferating (P) cells, then treated with BPA or BSH. Immediately after reactor neutron beam irradiation, during which intratumor 10B concentrations were kept at levels similar to each other, cells from some tumors were isolated and incubated with a cytokinesis blocker. The responses of BrdU-unlabeled quiescent (Q) and total (= P + Q) tumor cells were assessed based on the frequencies of micronucleation using immunofluorescence staining for BrdU.
Results
The CBE values were higher in Q cells and in the use of BPA than total cells and BSH, respectively. In addition, the higher the administered concentrations were, the smaller the CBE values became, with a clearer tendency in the use of BPA than BSH. The values for neutron capture agents that deliver into solid tumors more dependently on uptake capacity of tumor cells became more changeable.
Conclusion
Tumor characteristics, such as micro-environmental heterogeneity, stochastic genetic or epigenetic changes, or hierarchical organization of tumor cells, are thought to partially influence on the value of CBE, meaning that the CBE value itself may be one of the indices showing the degree of tumor heterogeneity.
doi:10.1186/2193-1801-3-128
PMCID: PMC4320213
Boron neutron capture therapy; Neutron capture agent; Relative biological effectiveness; Compound biological effectiveness; Tumor heterogeneity; Quiescent cell
23.  The hypoxia-selective cytotoxin NLCQ-1 (NSC 709257) controls metastatic disease when used as an adjuvant to radiotherapy 
British Journal of Cancer  2010;103(2):201-208.
Background:
Metastases cause most cancer-related deaths. We investigated the use of hypoxia-selective cytotoxins as adjuvants to radiotherapy in the control of metastatic tumour growth.
Methods:
The NLCQ-1, RB6145 and tirapazamine were assessed against the spontaneously metastasising KHT model. Subcutaneous KHT tumours (250 mm3) were irradiated with 25 Gy (single fraction) to control primary growth. Equitoxic drug treatments (NLCQ-1 (10 mg kg–1) once daily; RB6145 (75 mg kg–1) and tirapazamine (13 mg kg–1) twice daily) were administered 3–6 days post-radiotherapy when hypoxic cells were evident in lung micrometastases. Mice were culled when 50% of controls exhibited detrimental signs of lung metastases.
Results:
In total, 95% of control mice presented with lung disease. This was significantly reduced by NLCQ-1 (33% P=0.0002) and RB6145 (60% P=0.02). Semi-quantitative grading of lung disease revealed a significant improvement with all treatments, with NLCQ-1 proving most efficacious (median grades: control, 4; NLCQ, 0 (P<0.0001); RB6145, 1 (P<0.001), tirapazamine, 3 (P=0.007)). Positron emission tomography (PET) was evaluated as a non-invasive means of assessing metastatic development. Primary and metastatic KHT tumours showed robust uptake of [18F]fluorodeoxyglucose ([18F]FDG). Metastatic burden discernable by [18F]FDG PET correlated well with macroscopic and histological lung analysis.
Conclusion:
The hypoxia-selective cytotoxin NLCQ-1 controls metastatic disease and may be a successful adjuvant to radiotherapy in the clinical setting.
doi:10.1038/sj.bjc.6605753
PMCID: PMC2906743  PMID: 20588272
NLCQ-1 (NSC 709257); bioreductive; hypoxia; radiotherapy; metastasis; PET
24.  Antitumor effect of the angiogenesis inhibitor bevacizumab is dependent on susceptibility of tumors to hypoxia-induced apoptosis 
Biochemical pharmacology  2007;75(3):627-638.
Angiogenesis inhibition has been shown to enhance the therapeutic efficacy of cytotoxic chemotherapy in colorectal cancer. The basis of the contribution of this modality has not been defined fully. To determine the potential role of hypoxia-induced apoptosis, we studied a series of colon cancer cell lines with varying susceptibility to hypoxia. We exposed HT29 and HCT116 colon adenocarcinoma cell lines to sublethal periods of hypoxia three times weekly for 40 exposures, and derived cell lines both more resistant (from HT29) and more sensitive (from HCT116) to hypoxia-induced apoptosis. Both hypoxia-derived cell lines demonstrated more rapid growth than the parental lines when implanted subcutaneously in immunodeficient mice. Treatment of tumor-bearing mice with bevacizumab resulted in depletion of tumor microvasculature, upregulation of Hypoxia-inducible factor-1 alpha (HIF-1α), and increased pimonidazole staining, consistent with an anti-angiogenic effect and induction of hypoxia in tumors derived from all cell lines. The proportion of apoptotic cells was increased in all the treated tumors, and was most pronounced in the bevacizumab-treated HCT116-derived cells. The bevacizumab-treated tumors showed growth delay in HT29 and its derivative, and the parental HCT116. In the hypoxia-sensitive HCT116-derived tumors, marked tumor shrinkage and prolonged growth control occurred. Therefore, bevacizumab treatment is an effective inducer of a hypoxic environment, but the resulting cell kill and tumor shrinkage is determined by the susceptibility of the tumor to apoptosis. The induction of apoptosis by hypoxia may contribute to the benefits of such treatment in the clinical setting.
doi:10.1016/j.bcp.2007.09.029
PMCID: PMC2732335  PMID: 18178171
Hypoxia; VEGF; bevacizumab; and hypoxia-conditioned cell line
25.  Bevacizumab Suppression of Establishment of Micrometastases in Experimental Ocular Melanoma 
The administration of the anti-VEGF agent, bevacizumab, decreases tube formation and migration of human ocular melanoma cells, cultured alone or with HUVECs in vitro. The authors found that systemic bevacizumab decreased the size of ocular melanoma and the number of micrometastases in a mouse model of metastatic ocular melanoma. These findings are important with regard to a potential systemic therapy for patients with ocular melanoma with micrometastasis to the liver, as there is currently no effective treatment.
Purpose.
This study was undertaken to determine whether anti-vascular endothelial growth factor (VEGF) therapy inhibits growth of primary uveal melanoma and spread of its hepatic micrometastases.
Methods.
The human uveal melanoma cell lines Mel290 and Mel 270, HUVECs, mouse B16LS9 melanoma cells, and mouse vascular endothelial cells were separately cultured or co-cultured and incubated with bevacizumab or IgG1. The level of VEGF protein in the culture medium was measured by ELISA. In vitro angiogenesis and invasion assays were performed under bevacizumab or IgG1 treatment. Mel290 or B16LS9 cells were inoculated into NU/NU or C57Bl/6 mouse eyes which were enucleated after 7 days. The sizes of the intraocular tumors were determined. Time and dosage experiments were performed by using 50 or 250 μg bevacizumab starting at day 1 or 4 after inoculation. Hepatic micrometastases were enumerated. Proliferation, apoptosis, and angiogenesis markers were detected in the ocular tumor by immunofluorescence staining.
Results.
Bevacizumab significantly reduced the level of VEGF in the culture media from human uveal melanoma cells, mouse melanoma cells, and co-cultured cells. It also inhibited cell tube formation and decreased in vitro invasion of tumor cells. In the mouse model, bevacizumab suppressed primary ocular melanoma growth and the formation of hepatic micrometastases in a dose-dependent manner. Furthermore, immunohistochemical staining showed decreased Ki67 and unchanged caspase 3 expression after treatment with bevacizumab.
Conclusions.
Treatment with bevacizumab suppressed in vitro growth and in vivo hepatic micrometastasis of ocular melanoma cells. Bevacizumab is a potential therapeutic agent for the treatment of uveal melanoma micrometastases.
doi:10.1167/iovs.09-4755
PMCID: PMC2874122  PMID: 20089875

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