Peptide directorySkin, immune & repair

Thymosin beta-10

Thymosin beta-4’s smaller relative, more at home in the embryo and in tumours.

Where it comes from

Made in
Most cells, highest in the developing brain and in many cancers
Sent out by
Intracellular above all; released by injured cells
Acts on
  • Actin
  • Tumour and endothelial cells

What it does

  • Buffers actin like thymosin beta-4
  • Promotes or restrains tumour spread depending on the cancer studied
  • One of three peptides the subcommissural organ secretes into the fetal brain to support its development in mice 4

In medicine

  • No medicine, and nothing is measured through it in practice
  • Studied as a marker in several cancers: in papillary thyroid cancer the gene is amplified in the aggressive, metastatic tumours 2

Beyond the body’s own use

  • Not a treatment and not in trials. What is studied is its two faces in cancer: forced into tumour cells it bound Ras, cut off vessel growth and shrank human ovarian tumours in mice, the opposite of what its level in human tumours suggests 3
  • Whether it does anything outside the cell in people is unsettled: it has no receptor of its own, and the actin it binds is inside the cell 1

Sources

  1. Yu et al., Thymosin beta 10 and thymosin beta 4 are both actin monomer sequestering proteins, Journal of Biological Chemistry 1993
  2. Fehér et al., Amplification of thymosin beta 10 in aggressive papillary thyroid carcinomas, Pathology and Oncology Research 2012
  3. Lee et al., Thymosin beta-10 inhibits angiogenesis and tumour growth by interfering with Ras, Cancer Research 2005
  4. Zhang et al., The subcommissural organ regulates brain development via secreted peptides, Nature Neuroscience 2024

This card describes what a medicine is for and what the evidence says; it recommends nothing. Talk to your clinician about anything you read here.