The GHRH receptor splice variant SV1 was detected in 44% of oral squamous cell carcinomas versus only 9% of precancerous lesions, and GHRH antagonists blocked cancer cell growth in vitro.
44% of oral carcinomas express SV1Nearly half of oral squamous cell carcinomas expressed this GHRH receptor variant, compared to only 9% of precancerous lesions — a statistically significant jump (p<0.002) suggesting a role in malignant transformation.
What the researchers found
SV1 receptor immunoreactivity was detected in 44% (12 of 27) of oral squamous cell carcinomas compared to only 9% (3 of 33) of benign precancerous lesions (p<0.002). In cell culture, GHRH(1-29)NH2 and the GHRH agonist JI-38 stimulated HaCaT keratinocyte proliferation, and this growth stimulation was blocked by GHRH antagonists. The findings suggest SV1 expression may mark or contribute to malignant transformation in the oral epithelium.
Why it matters
Oral squamous cell carcinoma is a common and often aggressive cancer with limited targeted treatment options. Identifying SV1 as a receptor that appears during malignant transformation suggests a potential therapeutic target. Because GHRH antagonists are peptide-based and already in development for other cancers, this finding could accelerate new treatment approaches for oral cancer.
How the study worked
Researchers analyzed 33 benign precancerous oral lesions and 27 oral squamous cell carcinomas using immunohistochemistry for SV1 receptor expression. In parallel, they assessed SV1 expression in HaCaT keratinocytes by western blot and measured cell proliferation in response to GHRH agonists and antagonists via cell counting assays.
What this study cannot tell us
The sample sizes are small (27 carcinomas, 33 precancerous lesions), limiting statistical power for subgroup analyses. The in vitro proliferation studies used HaCaT keratinocytes rather than actual oral cancer cell lines, which may behave differently. The study demonstrates correlation between SV1 expression and malignancy but cannot prove causation. No in vivo treatment data with GHRH antagonists were generated.
How to read the evidence
This is a small observational study combining immunohistochemistry of human tissue samples with in vitro cell culture experiments. While the statistical comparison is significant, the sample sizes are modest and no therapeutic intervention was tested in vivo.
When this study was published
Published in 2012, this study identified a potential therapeutic target that remains relevant to ongoing research into peptide-based cancer therapies. The field has continued to develop GHRH antagonists since this publication.
The bigger picture
GHRH and its receptor variants have been implicated in multiple cancer types. This study extends that work to oral cancer, adding another tumor type where peptide-based GHRH antagonists could have therapeutic potential. The broader field of peptide hormone receptor-targeted cancer therapy continues to grow as researchers identify receptor overexpression in various malignancies.
Questions still open
- Does SV1 expression functionally drive the transition from precancerous oral lesions to squamous cell carcinoma, or is it merely a marker?
- Could GHRH antagonist peptides be effective in treating SV1-positive oral cancers in animal models or clinical settings?
- What determines which oral cancers express SV1 and could this guide patient selection for targeted therapy?
Common questions
What is GHRH and why does it matter for cancer?
Could GHRH antagonists treat oral cancer?
Read the original research
Growth hormone-releasing hormone receptor splice variant 1 is frequently expressed in oral squamous cell carcinomas.
Hormones & cancer, 3(4), 172-80
Citation
Dioufa, Nikolina; Farmaki, Elena; Schally, Andrew V; Kiaris, Hippokratis; Vlahodimitropoulos, Dimitris; Papavassiliou, Athanasios G; Kittas, Christos; Block, Norman L; Chatzistamou, Ioulia. (2012). Growth hormone-releasing hormone receptor splice variant 1 is frequently expressed in oral squamous cell carcinomas.. Hormones & cancer, 3(4), 172-80. https://doi.org/10.1007/s12672-012-0108-8