A potent GHRH receptor antagonist called MIA-602 effectively inhibited gastric cancer growth in cell cultures and mouse models by shutting down the PAK1-STAT3/NF-κB inflammatory signaling pathway.
Independent predictor of survivalGHRH receptor overexpression in gastric cancer tissues independently predicted poor patient survival across multiple cohorts, and the antagonist MIA-602 inhibited tumor growth in both lab and animal models
What the researchers found
Survival analysis across multiple cohorts of gastric cancer patients established that increased GHRH receptor expression in tumor tissue independently predicts poor survival. The GHRH receptor antagonist MIA-602 effectively inhibited gastric cancer cell growth in vitro across multiple human cell lines.
These results were confirmed in vivo using xenograft mouse models with human gastric cancer cells. Mechanistically, MIA-602 targets the GHRH receptor and downregulates the PAK1-mediated STAT3/NF-κB inflammatory pathway, providing a clear molecular explanation for its anticancer effects.
Why it matters
Gastric cancer is the fourth most common cancer and second deadliest worldwide, yet effective targeted therapies remain limited. This study published in PNAS establishes the GHRH receptor as both a prognostic biomarker and therapeutic target. The peptide-based antagonist approach is particularly notable because it targets a specific receptor-pathway axis, potentially offering more precision than standard chemotherapy with fewer side effects.
How the study worked
The study combined clinical and preclinical approaches. Survival analyses of multiple gastric cancer patient cohorts correlated GHRH receptor expression with prognosis. In vitro experiments tested MIA-602's effects on human gastric cancer cell line growth. In vivo efficacy was confirmed using multiple human gastric cancer cell line xenografts in nude mice. Molecular pathway analysis identified PAK1-STAT3/NF-κB as the downstream signaling mechanism affected by GHRH receptor antagonism.
What this study cannot tell us
The clinical survival data is retrospective and correlational — it shows GHRH-R expression predicts poor outcomes but does not prove causation. The in vivo work used immunodeficient nude mice with xenografts, which do not recapitulate the human immune response to cancer. No human clinical trials of MIA-602 for gastric cancer are reported. Specific tumor inhibition percentages and MIA-602 dosing details were not provided in the abstract. The study dates to 2016, and clinical translation progress is unclear.
How to read the evidence
Published in PNAS, this study combines retrospective patient survival data with preclinical in vitro and in vivo evidence. While the multi-level approach (clinical correlation + cell culture + animal models + mechanism) is rigorous, no human treatment data exists. The evidence is strong for preclinical work but preliminary for clinical translation.
When this study was published
Published in 2016 in PNAS, this study is now nearly a decade old. While the basic science findings about GHRH receptor biology in gastric cancer remain valid, the clinical translation status of MIA-602 and related GHRH antagonists should be verified with more recent literature.
The bigger picture
GHRH receptor antagonists represent part of a broader strategy of repurposing peptide hormone pathways for cancer treatment. Led in part by Nobel-adjacent researcher Andrew Schally, this line of work has explored GHRH antagonists against multiple cancer types. This study extends that work to gastric cancer and identifies a specific inflammatory pathway as the mechanism, connecting peptide endocrinology to cancer immunology and inflammation research.
Questions still open
- Has MIA-602 or a related GHRH receptor antagonist progressed to human clinical trials for any cancer type since this study?
- Would GHRH receptor antagonists work synergistically with immune checkpoint inhibitors, given the NF-κB inflammatory pathway involvement?
- Can GHRH receptor expression levels be used to select gastric cancer patients most likely to benefit from this targeted therapy?
Common questions
What is GHRH and why is its receptor important in cancer?
Is MIA-602 available as a cancer treatment?
Read the original research
Growth hormone-releasing hormone receptor antagonists inhibit human gastric cancer through downregulation of PAK1-STAT3/NF-κB signaling.
Proceedings of the National Academy of Sciences of the United States of America, 113(51), 14745-14750
Citation
Gan, Jinfeng; Ke, Xiurong; Jiang, Jiali; Dong, Hongmei; Yao, Zhimeng; Lin, Yusheng; Lin, Wan; Wu, Xiao; Yan, Shumei; Zhuang, Yixuan; Chu, Wai Kit; Cai, Renzhi; Zhang, Xianyang; Cheung, Herman S; Block, Norman L; Pang, Chi Pui; Schally, Andrew V; Zhang, Hao. (2016). Growth hormone-releasing hormone receptor antagonists inhibit human gastric cancer through downregulation of PAK1-STAT3/NF-κB signaling.. Proceedings of the National Academy of Sciences of the United States of America, 113(51), 14745-14750. https://doi.org/10.1073/pnas.1618582114