Ultrasensitive molecular profiling of EGFR mutations in glioblastoma multiforme using a rapid & high-resolution digital PCR approach

Glioblastoma Multiforme (GBM) is the most common and aggressive adult brain cancer with a 14.6-month average survival time, even with current therapies. 57% of GBM has amplified the Epidermal Growth Factor Receptor (EGFR). EGFR variant III, A289V, & R108K are mutations in EGFR that lead to increased tumor aggression and poorer prognosis. Learning more about these mutations will stop gliomas and prevent diminished survival, and shorter life expectancies in these patients. More quantitative methods of detection would allow for elucidation of mutations that occur during cancer development, with emphasis on metastasizing tumors. To inhibit EGFR in certain cancers, it is necessary to identify why increased proliferation occurs, usually because of mutation. After looking at the molecular changes in GBM, current methods of detection will be discussed, and finally, a novel method, digital Polymerase Chain Reaction (dPCR), will be introduced. While the detection of EGFR mutations in GBM tumors is arguably the best example for the utilization of dPCR, other applications of this technology will also be explored. Researchers have established very sensitive dPCR assays that detect various EGFR mutations in patient-derived tumors & organoids in only one day after resection surgery. RNA extracted from minute quantities of the patient tumor is converted to cDNA, which is then pre-amplified. Next, cDNA is run through a dPCR assay with a specially designed set of primers & probes for EGFR mutations and wild-type EGFR. In the future, RNA derived from microvesicles & platelets in a patient’s blood can be analyzed to help develop a less invasive characterization of tumors to eventually complement current diagnostic and treatment methods.Winner: First Place, 2021 Paul Robeson Library Undergraduate Research Award