Growth Hormone Receptor Emerges as Promising Target for Therapy-Resistant Lung Cancer
核心洞察
Ohio University researchers identified the growth hormone receptor as a key factor in lung cancer treatment resistance, with high receptor levels correlating to significantly shorter patient survival times.
Laboratory studies revealed that growth hormone makes cancer cells more resistant to chemotherapy by activating drug-efflux pumps that expel treatment drugs from cells.
The FDA-approved drug pegvisomant, which blocks growth hormone receptors, successfully reversed resistance mechanisms and enhanced chemotherapy effectiveness in laboratory models.
Researchers at Ohio University have identified a potential breakthrough in treating therapy-resistant lung cancer by targeting the growth hormone receptor, offering new hope for patients with one of the deadliest forms of cancer. The study, published in the International Journal of Molecular Science, reveals that blocking this receptor could significantly improve the effectiveness of existing treatments.
Growth Hormone Receptor Linked to Poor Survival Outcomes
The research team, led by Dr. John Kopchick, Goll-Ohio Eminent Scholar and distinguished professor at the Heritage College of Osteopathic Medicine, analyzed tumor samples from hundreds of non-small cell lung cancer (NSCLC) patients. NSCLC accounts for approximately 80-85 percent of all lung cancer cases and remains the leading cause of cancer-related death globally.
Using extensive patient datasets, including information from The Cancer Genome Atlas, researchers discovered that lung tumors exhibited significantly higher levels of growth hormone receptor (GHR) compared to normal lung tissue. The survival data revealed a stark difference: patients with low GHR levels survived an average of about 66 months, while those with high GHR levels survived only 36-40 months.
Mechanism of Treatment Resistance Revealed
Laboratory experiments with human and mouse lung cancer cells provided crucial insights into how growth hormone contributes to treatment resistance. The research showed that growth hormone made cancer cells more resistant to common chemotherapy drugs including doxorubicin and cisplatin through multiple mechanisms.
Growth hormone enhanced the activity of drug-efflux pumps - specialized proteins that essentially push chemotherapy out of cancer cells before it can do its job. Additionally, growth hormone triggered changes linked to tumor spread and reduced cell death, making the cancer significantly harder to treat and eliminate.
FDA-Approved Drug Shows Promise as Solution
The most promising aspect of the research involves pegvisomant, a drug already approved by the FDA for treating acromegaly, a condition caused by excess growth hormone. Pegvisomant, sold under the brand name Somavert, was originally discovered by Kopchick in 1987.
When researchers tested pegvisomant in laboratory models, it reversed many of growth hormone's harmful effects. The drug successfully increased the sensitivity of cancer cells to treatment and reduced the chemotherapy dose required to kill them. When combined with chemotherapy, pegvisomant made cancer cells significantly more sensitive to treatment.
"These findings suggest that growth hormone signalling helps drive aggressive and therapy-resistant lung cancer," said Kopchick. "By blocking the growth hormone receptor we may be able to improve the effectiveness of existing treatments."
Path to Clinical Application
Despite the encouraging laboratory results, researchers emphasize that significant work remains before this approach can reach patients. The current findings come from patient data analysis and laboratory cell models, requiring progression through animal testing before human clinical trials can begin.
Previous animal studies have demonstrated that combining pegvisomant with therapy significantly improved outcomes in melanoma, pancreatic and liver cancers in mouse models. The research team now plans to test the approach specifically in lung cancer mouse models. If these results prove positive, it could lead to clinical trials to determine whether this strategy is safe and effective for lung cancer patients.
The development timeline could span several years, as researchers must complete animal studies and navigate the clinical trial process. However, the fact that pegvisomant is already FDA-approved for another indication could potentially accelerate the regulatory pathway for lung cancer applications.
This research addresses a critical unmet need in lung cancer treatment, where many patients develop resistance to conventional therapies including surgery, chemotherapy, radiation and targeted treatments. The resistance mechanisms contribute to lower survival rates and make the disease increasingly difficult to control over time.