PLoS ONE (Jan 2024)

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

  • Masashi Okawa,
  • Munekazu Yamakuchi,
  • Aryal Bibek,
  • Kazunori Takenouchi,
  • Drew N Maywar,
  • Shingo Yamada,
  • Keiichi Inoue,
  • Kazuhiko Higurashi,
  • Junichi Nakazawa,
  • Masahiro Kawahira,
  • Tomoko Kodama,
  • Kiyonori Tanoue,
  • Yoko Oyama,
  • Sadayuki Higashi,
  • Chieko Fujisaki,
  • Hirohito Hashinokuchi,
  • Akito Tabaru,
  • Hideaki Kanda,
  • Shuji Tachioka,
  • Yutaka Imoto,
  • Teruto Hashiguchi,
  • Yoshiharu Soga

DOI
https://doi.org/10.1371/journal.pone.0316035
Journal volume & issue
Vol. 19, no. 12
p. e0316035

Abstract

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BackgroundVEGF-A concentrations were measured in the blood of bevacizumab-treated cancer patients in previous studies, but a consensus has not formed that would develop VEGF-A into a clinical biomarker. Recently, methods to strictly distinguish between the VEGF-A isoforms have been developed but have not yet been applied to cancer patients undergoing bevacizumab treatment.MethodsAn ELISA that strictly distinguishes between VEGF-A121 and VEGF-A165-the major isoforms of VEGF-A-and a commercially available ELISA for VEGF-A are used to determine the concentration of VEGF-A121, VEGF-A165, and VEGF-A in the blood of 12 patients with advanced colorectal cancer receiving bevacizumab therapy.ResultsThe serum and plasma concentrations of VEGF-A121 increased substantially post-bevacizumab administration; the median increase in serum was 860.8 pg/mL, 95% confidence interval (CI) [468.5, 1128.9], p = 0.0024, and in plasma was 808.6 pg/mL, 95% CI [748.7, 874.0], p = 0.00049. In stark contrast, VEGF-A165 after bevacizumab administration decreased in serum by a medium change of -73.8 pg/mL, 95% CI [-149.4, -10.2], p = 0.0034, with 83.3% of the post-bevacizumab concentrations falling below the high-accuracy threshold of 38 pg/mL; in plasma, all pre and post VEGF-A165 concentrations fell below this threshold. Concentrations of VEGF-A121 and VEGF-A165 in platelets did not change to a statistically significant degree. Adding recombinant VEGF-A121 (and -A165) or bevacizumab to plasma in patients post-bevacizumab administration increased or decreased, respectively, VEGF-A121 and VEGF-A165 levels. The increase in VEGF-A121 in plasma and serum after bevacizumab administration may be due to the dissociation of the complex of tumor-derived VEGF-A121 and bevacizumab when it moves from the stroma into the blood.ConclusionsThe VEGF-A121 isoform has been uniquely demonstrated as a clear marker of bevacizumab therapy in both plasma and serum, motivating further research on pursuing these isoforms as biomarkers in cancer care.