Ghrelin, the endogenous
ligand for the GH
secretagogue receptor (GHSR), is a
peptide hormone with diverse physiological roles.
Ghrelin regulates GH release, appetite and feeding, gut motility, and energy balance and also has roles in the cardiovascular, immune, and reproductive systems.
Ghrelin and the GHSR are expressed in a wide range of normal and
tumor tissues, and a
fluorescein-labeled, truncated form of
ghrelin is showing promise as a
biomarker for
prostate cancer. Plasma
ghrelin levels are generally inversely related to body mass index and are unlikely to be useful as a
biomarker for
cancer, but may be useful as a marker for
cancer cachexia. Some single nucleotide polymorphisms in the
ghrelin and GHSR genes have shown associations with
cancer risk; however, larger studies are required.
Ghrelin regulates processes associated with
cancer, including cell proliferation, apoptosis, cell migration, cell invasion,
inflammation, and angiogenesis; however, the role of
ghrelin in
cancer is currently unclear.
Ghrelin has predominantly antiinflammatory effects and may play a role in protecting against
cancer-related
inflammation.
Ghrelin and its analogs show promise as treatments for
cancer-related
cachexia. Further studies using in vivo models are required to determine whether
ghrelin has a role in
cancer progression.