GHRH-knockout mice developed significantly more and larger colon tumors with invasive cancer when exposed to carcinogens, suggesting GHRH has a protective anti-inflammatory role.
Invasive vs non-invasiveGHRH-/- mice developed invasive adenocarcinomas while wild-type mice only developed benign adenomas
What the researchers found
GHRH-deficient mice showed significantly increased tumor number, size, and invasiveness in a colon carcinogenesis model, with elevated COX-2, TNF-α, NF-κB, and iNOS.
Why it matters
This challenges the simplistic view that growth hormone signaling always promotes cancer. GHRH may actually protect against inflammation-driven cancers, which has implications for anti-aging interventions that suppress the somatotropic axis.
The numbers in context
KO: more tumors, larger, distal colon, invasive adenocarcinomas; WT: adenomas only; KO higher PGE2, COX-2, TNF-α, NF-kB, iNOS
How the study worked
GHRH knockout vs wild-type mice treated with AOM/DSS chemical carcinogenesis protocol. Endpoints: tumor count/size, histopathology, Disease Activity Index, inflammatory marker gene expression, PGE2 and 8-iso-PGF2α levels.
Who was studied
GHRH knockout and wild-type C57BL/6 mice with AOM/DSS-induced colon cancer
What this study cannot tell us
Male mice only; cannot distinguish whether effects are from GHRH loss or secondary GH deficiency; group sizes not specified; chemical carcinogenesis model may not fully represent human colon cancer.
How to read the evidence
Moderate — well-designed knockout mouse study with multiple endpoints, but unspecified group sizes and male-only design.
When this study was published
Published in 2020; the relationship between the GH axis and cancer continues to be debated.
The bigger picture
The growth hormone axis is a double-edged sword in cancer. While GH/IGF-1 excess may promote some cancers, this study shows complete GHRH absence worsens inflammation-associated carcinogenesis — important for the longevity field that targets GH reduction.
Questions still open
- Is the cancer-promoting effect due to missing GHRH directly or the resulting GH deficiency?
- Would GHRH replacement therapy restore the protective effect?
- Do humans with GH deficiency have increased colon cancer risk?
Common questions
Doesn't growth hormone promote cancer?
What is AOM/DSS?
Read the original research
Growth hormone-releasing hormone (GHRH) deficiency promotes inflammation-associated carcinogenesis.
Pharmacological research, 152, 104614
Citation
Leone, Sheila; Chiavaroli, Annalisa; Recinella, Lucia; Di Valerio, Valentina; Veschi, Serena; Gasparo, Irene; Bitto, Alessandra; Ferrante, Claudio; Orlando, Giustino; Salvatori, Roberto; Brunetti, Luigi. (2020). Growth hormone-releasing hormone (GHRH) deficiency promotes inflammation-associated carcinogenesis.. Pharmacological research, 152, 104614. https://doi.org/10.1016/j.phrs.2019.104614