Related Experiment Video

Updated: Jan 26, 2026

Immunofluorescence Imaging of DNA Damage and Repair Foci in Human Colon Cancer Cells
05:18

Immunofluorescence Imaging of DNA Damage and Repair Foci in Human Colon Cancer Cells

Published on: June 9, 2020

11.8K

Growth Hormone Induces Colon DNA Damage Independent of IGF-1

Vera Chesnokova1, Svetlana Zonis1, Robert J Barrett2

  • 1Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California.

Endocrinology
|April 20, 2019
PubMed

Insights

Growth hormone (GH) directly increases DNA damage in colon cells, independent of IGF-1 signaling. Suppressing the IGF-1 receptor enhances GH

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Genetics

Background:

  • DNA damage from environmental factors and aging can cause genomic instability and cancer.
  • Growth hormone (GH) is known to suppress DNA repair mechanisms, potentially increasing DNA damage.
  • The role of Insulin-like Growth Factor 1 (IGF-1) in mediating GH's effect on DNA damage requires clarification.

Purpose of the Study:

  • To investigate whether GH-induced DNA damage is mediated by IGF-1.
  • To explore the direct effects of GH on DNA damage in human colon cells.
  • To elucidate the role of the GH receptor (GHR) and IGF-1 receptor (IGF-1R) in GH's impact on DNA damage.

Main Methods:

  • In vitro studies using human colon cells with disrupted IGF-1R via short hairpin RNA.
  • In vitro and in vivo experiments using the IGF-1R inhibitor picropodophyllotoxin (PPP).
  • Xenograft mouse models with GH-secreting tumors and PPP treatment; analysis of GHR and IGF-1R activity.
  • Comparison of DNA damage in GHR knockout (GHR-/-) and wild-type mice.

Main Results:

  • GH, but not IGF-1 alone, increased DNA damage in normal human colon cells.
  • Disrupting IGF-1R signaling led to increased GHR abundance and heightened cellular responsiveness to GH.
  • GH treatment further exacerbated DNA damage in cells with suppressed IGF-1R.
  • In vivo studies confirmed that GH increases colon DNA damage independently of IGF-1R activity, correlating with induced GHR levels.
  • GHR knockout mice showed no increased DNA damage when IGF-1 signaling was suppressed, unlike wild-type mice.

Conclusions:

  • GH directly induces DNA damage in colon cells, a process independent of IGF-1 signaling.
  • The effects of GH on DNA damage are primarily mediated through the GH receptor (GHR), not the IGF-1 receptor (IGF-1R).
  • Suppression of IGF-1R signaling can potentiate GH-induced DNA damage by upregulating GHR expression.

More Related Videos

Using Immunofluorescence to Detect PM2.5-induced DNA Damage in Zebrafish Embryo Hearts05:58

Using Immunofluorescence to Detect PM2.5-induced DNA Damage in Zebrafish Embryo Hearts

Published on: February 15, 2021

4.3K
Demonstration of the DNA Fiber Assay for Investigating DNA Damage and Repair Dynamics Induced by Nanoparticles13:09

Demonstration of the DNA Fiber Assay for Investigating DNA Damage and Repair Dynamics Induced by Nanoparticles

Published on: March 3, 2023

5.0K

Related Concept Videos

Hormonal Regulation01:40

Hormonal Regulation

Hormones regulate a significant portion of digestion through activation of the neuroendocrine system. The neuroendocrine system of digestion contains many different hormones all with multiple functions that are both, directly and indirectly, involved in digestion.
48.0K
Hormonal Regulation01:33

Hormonal Regulation

The renin-aldosterone system is an endocrine system which guides the renal absorption of water and electrolytes, thus managing blood pressure and osmoregulation. Activation of the system begins in the kidneys with a small cluster of cells adjacent to the afferent and efferent blood vessels of the renal corpuscle. As the nephrons are filtering blood, juxtaglomerular cells monitor blood pressure. If they detect a decrease in pressure, they release the hormone renin into the bloodstream.
35.8K
Plant Hormones01:56

Plant Hormones

Plant hormones—or phytohormones—are chemical molecules that modulate one or more physiological processes of a plant. In animals, hormones are often produced in specific glands and circulated via the circulatory system. However, plants lack hormone-producing glands.
27.4K
Types of Hormones02:13

Types of Hormones

Hormones can be classified into three main types based on their chemical structures: steroids, peptides, and amines. Their actions are mediated by the specific receptors they bind to on target cells.
83.3K
DNA Damage Can Stall the Cell Cycle02:36

DNA Damage Can Stall the Cell Cycle

In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
3.1K
DNA Damage can Stall the Cell Cycle02:36

DNA Damage can Stall the Cell Cycle

In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
10.0K