The GHRH receptor splice variant SV1 is activated by hypoxia in esophageal cancer and drives tumor progression through enhanced glycolysis, but can be reversed by GHRH-R antagonist MIA-602.
SV1GHRH receptor splice variant identified as the actual target of GHRH-R antagonists in cancers without standard receptor
What the researchers found
Hypoxia-elevated SV1 splice variant activates PFKM through the NF-κB pathway, enhancing glycolytic metabolism and promoting esophageal cancer progression. GHRH-R antagonist MIA-602 reversed these malignant effects by targeting SV1.
Why it matters
This study explains a longstanding puzzle — why GHRH-R antagonists work against cancers that don't express the standard receptor — and identifies SV1 as the actual therapeutic target, potentially expanding the use of these drugs to more cancer types.
The numbers in context
SV1 variant expressed in ESCC; standard pGHRH-R absent; GHRH-R antagonists significantly suppressed tumor growth.
How the study worked
Esophageal squamous cell carcinoma cell models with hypoxia exposure, signaling pathway analysis (NF-κB, PFKM), metabolic profiling, and in vivo validation. MIA-602 treatment tested against SV1-driven tumor progression.
Who was studied
Esophageal squamous cell carcinoma cell lines and mouse xenograft models
What this study cannot tell us
Focused on esophageal squamous cell carcinoma; generalizability to other cancer types expressing SV1 needs validation. MIA-602 is an experimental compound not yet in clinical use.
How to read the evidence
Combined in vitro and in vivo evidence with clear mechanistic pathway identified. Pre-clinical stage with an experimental antagonist compound.
When this study was published
Published in 2020. GHRH-R antagonist research continues with interest in targeting splice variants across cancer types.
The bigger picture
Understanding which receptor variants mediate drug effects is crucial for expanding cancer therapy options. The SV1 target discovery could help identify which patients are most likely to benefit from GHRH-R antagonist therapy across multiple cancer types.
Questions still open
- Is SV1 expression a useful biomarker for selecting patients likely to respond to GHRH-R antagonists?
- Do other cancers that respond to GHRH-R antagonists also rely on the SV1 pathway?
- How does the SV1-targeting mechanism of MIA-602 differ from its action on the standard GHRH receptor?
Common questions
What is a splice variant?
Why does low oxygen promote cancer growth?
Read the original research
Splice variant of growth hormone-releasing hormone receptor drives esophageal squamous cell carcinoma conferring a therapeutic target.
Proceedings of the National Academy of Sciences of the United States of America, 117(12), 6726-6732
Citation
Xiong, Xiao; Ke, Xiurong; Wang, Lu; Yao, Zhimeng; Guo, Yi; Zhang, Xianyang; Chen, Yuping; Pang, Chi Pui; Schally, Andrew V; Zhang, Hao. (2020). Splice variant of growth hormone-releasing hormone receptor drives esophageal squamous cell carcinoma conferring a therapeutic target.. Proceedings of the National Academy of Sciences of the United States of America, 117(12), 6726-6732. https://doi.org/10.1073/pnas.1913433117