In a fascinating discovery that could reshape brain cancer treatment approaches, scientists have found that glioblastoma, an aggressive brain cancer, synchronizes its internal clock with the body’s natural rhythms to optimize its growth. This discovery reveals how these deadly tumors exploit our body’s normal biological timing mechanisms and suggests new timing-based therapeutic strategies.
Published in Cancer Cell | Estimated reading time: 5 minutes
The human body operates on a complex system of internal clocks, with each cell following daily rhythms orchestrated by a master timekeeper in the brain. Now, researchers at Washington University in St. Louis have discovered that glioblastoma tumors have learned to exploit this same timing system to enhance their growth.
“Glioblastoma takes its cues from hormones released by the same central clock in the host that establishes the body’s regular daily rhythms,” explains Erik D. Herzog, PhD, the Viktor Hamburger Distinguished Professor and senior author of the study.
The research team found that these brain tumors respond to the body’s daily release of steroid hormones, particularly glucocorticoids. Each day, just before waking, our brain signals the adrenal glands to release these hormones, which typically help regulate metabolism and immunity. However, glioblastoma cells have hijacked this natural rhythm to their advantage.
The implications of this discovery extend to current treatment practices, particularly regarding dexamethasone (DEX), a synthetic steroid commonly prescribed to glioblastoma patients. The timing of DEX administration appears crucial – evening doses showed tumor suppression, while morning doses promoted tumor growth in experimental models.
Maria F. Gonzalez-Aponte, PhD, the study’s first author, utilized an innovative approach to track cancer cell behavior. By monitoring tumor-bearing mice under controlled light conditions, the team observed that cancer cells adjusted their rhythms to match the host’s schedule, demonstrating a sophisticated ability to synchronize with the body’s natural timing.
The research offers hope for improving patient outcomes. Data analysis revealed that “glioblastoma patients tend to live 60% longer if their tumor expressed less glucocorticoid receptor,” suggesting potential new therapeutic strategies based on timing of treatments.
Glossary
- Glioblastoma
- An aggressive, incurable form of brain cancer that is the most common malignant brain tumor in adults.
- Glucocorticoids
- Steroid hormones involved in the body’s fight-or-flight response and regulation of metabolism and immunity.
- Circadian Rhythms
- Daily biological cycles that regulate essential processes including sleep, eating patterns, and body temperature.
Test Your Knowledge
What happens to glucocorticoid levels in the body just before waking?
They increase dramatically as part of the body’s natural daily rhythm.
How do glioblastoma tumors respond to the host’s daily rhythms?
They synchronize their internal clock to match the host’s daily rhythms and take advantage of regular hormone releases.
What was discovered about the timing of dexamethasone (DEX) treatment?
Morning administration promoted tumor growth, while evening administration suppressed growth in experimental models.
What correlation was found between glucocorticoid receptors and patient survival?
Patients whose tumors expressed fewer glucocorticoid receptors showed 60% longer survival rates.
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