Scientists have revealed an encouraging development in the understanding of brain cancer.
The researchers at the University of California, San Diego School of Medicine in the United States have identified a biomarker that predicts whether glioblastoma – the most common form of primary brain cancer – will respond to chemotherapy.
According to the lead investigator, the work will reduce the administration of treatments from which the patient will derive little benefit.
Clark C. Chen, MD, PhD, vice-chairman of Academic Affairs, Division of Neurosurgery, UC San Diego School of Medicine and the study’s principal investigator, said: “Every patient diagnosed with glioblastoma is treated with a chemotherapy called temozolomide. About 15 per cent of these patients derive long-lasting benefit.
“We need to identify which patients benefit from temozolomide and which another type of treatment. All therapies involve risk and the possibility of side-effects. Patients should not undergo therapies if there’s no likelihood of benefit.”
The researchers studied microRNAs that control the expression of a protein called methyl-guanine-methyl-transferase or MGMT, which reduces the cancer-killing effect of temozolomide. Tumours with high levels of MGMT are associated with a poor response to temozolomide therapy.
The scientists tested every microRNA in the human genome to identify those that suppressed MGMT expression.
Clark C. Chen said: “Validation of these results should lead to diagnostic tools to enable us to determine which patients will benefit most from temozolomide therapy.”
The team also discovered that injection of the MGMT-regulating microRNAs into glioblastoma cells increased the way tumours respond to temozolomide treatment.
Lead author, Valya Ramakrishnan, PhD, postdoctoral researcher, UC San Diego School of Medicine, said: “These findings establish the foundation for microRNAs-based therapies to increase the efficacy of temozolomide in glioblastoma patients.”
Funding for the research came, in part, from the Sontag Foundation, Burroughs Wellcome Foundation, Kimmel Foundation and the Forbeck Foundation.