Journal: PLOS ONE

Article Title: Plasma and serum concentrations of VEGF-A121, but not of VEGF-A165, increase post-bevacizumab administration

doi: 10.1371/journal.pone.0316035

Figure Lengend Snippet: VEGF-A121, VEGF-A165, and VEGF-A concentrations in plasma ( a - c ) and in serum ( d - f ) were measured pre- and post-bevacizumab administration, showing that only VEGF-A121 is a clear marker of bevacizumab therapy in both plasma and serum. a Plasma VEGF-A121 exhibited a median increase of 808.6 pg/mL, 95% CI [748.7, 874.0], p = 0.00049. b Plasma VEGF-A165 concentration was below the high-accuracy threshold, both pre- and post-administration, and exhibited a statistically insignificant median change of 0 pg/mL, 95% CI [–1.7, –1.6], p = 0.3125. c Plasma VEGF-A exhibited a median change of 156.9 pg/mL, 95% CI [126.8, 190.0], p = 0.00026. d Serum VEGF-A121 exhibited a median increase of 860.8 pg/mL, 95% CI [468.5, 1128.9], p = 0.0024. e Serum VEGF-A165 exhibited a medium change of –73.8 pg/mL, 95% CI [–149.4, –10.2], p = 0.0034, with 10 of 12 (83.3%) of the post-bevacizumab concentrations falling below the high-accuracy threshold of 38 pg/mL. f Serum VEGF-A exhibited a median change of –86.1 pg/mL, 95% CI [–545.4, 88.74], p = 0.1763.

Article Snippet: Expression plasmids for hVEGF-A121 (#HG10008-NF) and hVEGF-A165 (#RC229662) were purchased from Sino Biological (Beijing, China) and OriGene Technologies (Rockville, MD), respectively.

Techniques: Marker, Concentration Assay

Journal: PLOS ONE

Article Title: Plasma and serum concentrations of VEGF-A121, but not of VEGF-A165, increase post-bevacizumab administration

doi: 10.1371/journal.pone.0316035

Figure Lengend Snippet: Concentrations of VEGF-A121, VEGF-A165, and VEGF-A in the platelet lysates, showing that the amounts of VEGF-A and its isoforms in platelets do not change to a statistically significant degree between pre- and post-bevacizumab administration. a VEGF-A121 exhibited a median change of –0.03 pg/10 6 platelets, 95% CI [–0.08, 0.14], p = 0.625. b VEGF-A165 exhibited a median change of –0.02 pg/10 6 platelets, 95% CI [–0.004, 0.129], p = 0.250. c VEGF-A exhibited a median change of –0.117 pg/10 6 platelets, 95% CI [–0.374, 0.301], p = 0.556.

Article Snippet: Expression plasmids for hVEGF-A121 (#HG10008-NF) and hVEGF-A165 (#RC229662) were purchased from Sino Biological (Beijing, China) and OriGene Technologies (Rockville, MD), respectively.

Techniques:

Journal: PLOS ONE

Article Title: Plasma and serum concentrations of VEGF-A121, but not of VEGF-A165, increase post-bevacizumab administration

doi: 10.1371/journal.pone.0316035

Figure Lengend Snippet: Bevacizumab absorbed VEGF-A121 and VEGF-A165 in a dose dependent manner. a and b show the results of bevacizumab addition to rhVEGF-A. a Bevacizumab was added at 1, 10, and 100 μg/mL to rhVEGF-A121, adjusted to a concentration of 100 ng/mL. After the one-way ANOVA test, a test of linear trend between column means and column order from left to right was performed for multiple comparisons, and a linear trend was observed between VEGF-A121 and bevacizumab concentrations (ANOVA: p < 0.0001; test for trend: p < 0.0001). b Similar experiments were performed using VEGF-A165 (ANOVA: p < 0.0001; test for trend: p < 0.0001). c and d show the results of bevacizumab addition to the culture medium of HEK293 cells transfected with VEGF-A. c HEK293 cells were transfected with VEGF-A121 and cultured in a medium containing 1, 10, or 100 μg/mL bevacizumab, and in a culture medium without bevacizumab (control). The culture medium was collected, and VEGF-A121 concentrations were measured. The same test was performed, and a linear trend was observed (ANOVA, p < 0.0001; test for trend, p < 0.0001). d The same experiment was performed for VEGF-A165 (ANOVA: p < 0.0001; test for trend: p < 0.0001).

Article Snippet: Expression plasmids for hVEGF-A121 (#HG10008-NF) and hVEGF-A165 (#RC229662) were purchased from Sino Biological (Beijing, China) and OriGene Technologies (Rockville, MD), respectively.

Techniques: Concentration Assay, Transfection, Cell Culture, Control

Journal: PLOS ONE

Article Title: Plasma and serum concentrations of VEGF-A121, but not of VEGF-A165, increase post-bevacizumab administration

doi: 10.1371/journal.pone.0316035

Figure Lengend Snippet: Addition of rhVEGF-A (-121 or-165; 1,000 pg/mL or 10,000 pg/mL) to plasma samples pre- and post-bevacizumab administration, and the magnitude of change associated with the addition was calculated by subtracting the concentration in plasma samples without rhVEGF-A from the concentration in plasma samples with rhVEGF-A added. a Plasma samples pre-bevacizumab administration showed an increase in VEGF-A121 concentration (mean ± SD: 655 ± 44 pg/mL) corresponding to the addition of 1,000 pg/mL of rhVEGF-A121; plasma samples post-bevacizumab administration showed no increase in the concentration corresponding to the addition (mean ± SD: 15 ± 18 pg/mL). b Similarly, the addition of 1,000 pg/mL of rhVEGF-A165 increased the concentration of VEGF-A165 in plasma samples pre-bevacizumab administration (mean ± SD: 670 ± 102 pg/mL), whereas the increase in concentration was negligible in plasma samples post-bevacizumab administration (mean ± SD: 38 ± 9 pg/mL). c Addition of 10,000 pg/mL rhVEGF-A121 increased the concentration of VEGF-A121 in plasma samples pre-bevacizumab administration (mean ± SD: 4,624 ± 1,500 pg/mL), whereas the increase in concentration was negligible in plasma samples post-bevacizumab administration (mean ± SD: 96 ± 92 pg/mL). d Addition of 10,000 pg/mL rhVEGF-A165 increased the concentration of VEGF-A165 in plasma samples pre-bevacizumab administration (mean ± SD: 3,121 ± 1,236 pg/mL), whereas the increase in concentration was negligible in plasma samples post-bevacizumab administration (mean ± SD: 409 ± 134 pg/mL).

Article Snippet: Expression plasmids for hVEGF-A121 (#HG10008-NF) and hVEGF-A165 (#RC229662) were purchased from Sino Biological (Beijing, China) and OriGene Technologies (Rockville, MD), respectively.

Techniques: Concentration Assay

Journal: PLOS ONE

Article Title: Plasma and serum concentrations of VEGF-A121, but not of VEGF-A165, increase post-bevacizumab administration

doi: 10.1371/journal.pone.0316035

Figure Lengend Snippet: Serum samples pre-bevacizumab administration were treated with or without bevacizumab (2 μg/mL). Serum samples after bevacizumab treatment with an additional 2, 20, or 200 μg/mL of bevacizumab were compared to control samples without bevacizumab, indicating that free VEGF-A121 remained even at high doses of bevacizumab addition. a VEGF-A121 exhibited a change of –173.2, 95% CI [–322.8, –96.3], p = 0.00049, where the addition of 2 μg/mL bevacizumab markedly reduced the VEGF-A121 concentration to a median of 26.9 pg/mL, with a range of 67.3 pg/mL that partly fell below the high-accuracy threshold of 38 pg/mL. b VEGF-A165 concentrations exhibited a change of –46.4, 95% CI [–101.4, –16.6], p = 0.0015, driven down to a median of 2.9 pg/mL with a range of 14.12 pg/mL that is entirely below the high-accuracy threshold. c Further addition of bevacizumab to serum samples post-bevacizumab administration significantly decreased VEGF-A121 levels in samples to which 20 and 200 μg/mL bevacizumab was added (ANOVA: p < 0.0001; Dunnett’s multiple comparisons test: +2 μg/mL, p = 0.7096 vs control; +20 μg/mL, p = 0.0107 vs control; +200 μg/mL, p < 0.0001 vs control). d VEGF-A165 concentrations were low in serum samples post-bevacizumab administration and remained low after further addition of bevacizumab. e The percent change in VEGF-A121 concentration with the addition of any (2, 20, or 200 μg/mL) concentration of bevacizumab to serum samples post-bevacizumab administration was significantly less than the percent change in VEGF-A121 concentration with the addition of 2 μg/mL concentration of bevacizumab to serum samples pre-bevacizumab administration (ANOVA: p < 0.0001; Dunnett’s multiple comparisons test: Post+2 μg/mL, p < 0.0001 vs Pre+2 μg/mL; Post +20 μg/mL, p < 0.0001 vs Pre+2 μg/mL; +200 μg/mL, p < 0.0001 vs Pre+2 μg/mL).

Article Snippet: Expression plasmids for hVEGF-A121 (#HG10008-NF) and hVEGF-A165 (#RC229662) were purchased from Sino Biological (Beijing, China) and OriGene Technologies (Rockville, MD), respectively.

Techniques: Control, Concentration Assay

Journal: PLOS ONE

Article Title: Plasma and serum concentrations of VEGF-A121, but not of VEGF-A165, increase post-bevacizumab administration

doi: 10.1371/journal.pone.0316035

Figure Lengend Snippet: Serum samples pre- and post-bevacizumab administration were immunoprecipitated to remove the VEGF-A–bevacizumab complex and the isoform concentrations were measured in the remaining serum samples, showing that VEGF-A121 post administration exhibited the most substantial change. a Pre-administration, VEGF-A121 exhibited a median change of –37.3 pg/mL, 95% CI [–54.6, –16.0], p = 0.00049. b Pre-administration, VEGF-A165 exhibited a statistically insignificant median change of –18.1 pg/mL, 95% CI [–34.2, 7.5], p = 0.1475 c Post-administration, VEGF-A121 exhibited a substantial median change of –771.8 pg/mL, 95% CI [–970.9, –567.5], p = 0.00049. d Post-administration VEGF-A165 exhibited a small median change of –12.5 pg/mL, 95% CI [–23.4, –6.1], p = 0.0210. e Due to the possibility of nonspecific removal of VEGF-A using immunoprecipitation, the rate of change in VEGF-A121 concentration due to immunoprecipitation was compared pre- and post-bevacizumab administration and was reduced more by immunoprecipitation in specimens post-bevacizumab administration.

Article Snippet: Expression plasmids for hVEGF-A121 (#HG10008-NF) and hVEGF-A165 (#RC229662) were purchased from Sino Biological (Beijing, China) and OriGene Technologies (Rockville, MD), respectively.

Techniques: Immunoprecipitation, Concentration Assay

Journal: PLOS ONE

Article Title: Plasma and serum concentrations of VEGF-A121, but not of VEGF-A165, increase post-bevacizumab administration

doi: 10.1371/journal.pone.0316035

Figure Lengend Snippet: The left panel shows the condition pre-bevacizumab administration. VEGF-A121 is present at high concentrations in the tumor stroma; VEGF-A165 binds to the interstitial matrix and vessel walls for binding to HSPG. Right panel shows the condition post-bevacizumab administration. Free VEGF-A121 in the tumor stroma and free VEGF-A121 in the plasma reach an equal concentration; thus, the plasma VEGF-A121 concentration increases and the VEGF-A121 concentration in the tumor stroma decreases.

Article Snippet: Expression plasmids for hVEGF-A121 (#HG10008-NF) and hVEGF-A165 (#RC229662) were purchased from Sino Biological (Beijing, China) and OriGene Technologies (Rockville, MD), respectively.

Techniques: Binding Assay, Concentration Assay