Organ size control by Hippo and TOR pathways

Karen Tumaneng1, Ryan C Russell, Kun-Liang Guan

  • 1Department of Pharmacology and Sanford Consortium for Regenerative Medicine, University of California at San Diego, La Jolla, CA 92093, USA.

Insights

Organ size is tightly controlled by cell number and size regulation. This review explores how the Hippo and Target of Rapamycin (TOR) pathways coordinate to manage organ growth, impacting diseases like cancer.

Area of Science:

  • Developmental Biology
  • Cell Signaling
  • Physiology

Background:

  • Organ size determination is a complex process regulated by cell number and size.
  • Dysregulation of organ size control is implicated in diseases such as cancer and hypertrophy.
  • The Hippo and Target of Rapamycin (TOR) signaling pathways are critical regulators of organ growth.

Purpose of the Study:

  • To review general mechanisms of organ growth regulation.
  • To describe the roles of Hippo and TOR pathways in controlling cell number and size.
  • To discuss potential coordination between Hippo and TOR in organ size control.

Main Methods:

  • Literature review of organ growth mechanisms.
  • Analysis of Hippo pathway functions in cell number regulation.
  • Analysis of TOR pathway functions in cell size regulation.

Main Results:

  • Organ size is precisely regulated by controlling cell proliferation, cell growth, and apoptosis.
  • The Hippo pathway primarily regulates organ size by controlling cell proliferation and apoptosis.
  • The TOR pathway primarily regulates organ size by controlling cell growth and metabolism.

Conclusions:

  • The Hippo and TOR pathways are key regulators of organ size.
  • Recent findings suggest a coordination between Hippo and TOR pathways in organ size regulation.
  • Understanding this coordination may offer insights into treating diseases related to organ size dysregulation.

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