Gene Analysis and Interpretation of Medulloblastomas
Updated: Jun 14
By Samiha Nasrin
With over 700,000 people diagnosed with a brain tumor in the US alone per year, neurological diseases such as this affect a wide population today. With no current pre-screening methods for these neurological conditions, there have been instances where a diagnosis of these brain tumors are often too late for surgical extraction or other procedures. As a result, many neurologists have been looking into the possible causes of brain tumors to diagnose them effectively; one of these causes is genetics.
This is exactly what Dr. Chetan Bettegowda has been doing at the Johns Hopkins Comprehensive Brain Tumor Center. Primarily focusing on the various genetic pathways in the brain & nervous system, Dr. Bettegowda has put an emphasis on the genetic implications of medulloblastomas.
Medulloblastomas is a malignant brain tumor often found in the back of the brain, otherwise known as the cerebellum. The cerebellum is most commonly named the “little brain,” as it can control a human’s voluntary movements and motor learning. Starting at the cerebellum, the cancerous tissue cells in a medulloblastoma can quickly spread to other parts of the brain through cerebral spinal fluid (CSF). This condition is often found in pediatric patients, and requires extensive treatments such as surgery, radiation therapy, and chemotherapy depending on the severity of the tumor.
Since there is no pre-screening method for these brain conditions, many patients tend to experience symptoms such as dizziness and headaches for months on end until an official diagnosis is introduced. Current screening methods such as magnetic resonance imaging (MRI) can detect brain masses caused by this condition, but it can not display a pre diagnosis even before the tumor is formed. Dr. Bettegowda is researching to provide early diagnosis methods for medulloblastomas using gene analysis.
By doing a cross-examination with cerebral spinal fluid, RNA and lipid analysis can suggest certain trends that align with the emergence of glioblastomas. In Dr. Bettegowda’s clinical trial, biopsies of CSF from different patients underwent RNA extraction using the miRNeasy Mini and RNA Clean & Concentrator kit. The cDNA produced from these procedures then underwent qRT-PCR testing in order to obtain a viable sample of genetic material for further analysis.
The results of this experiment were substantial and clinically significant. Over 48 of the genes tested in the CSF samples from patients diagnosed with medulloblastomas had varied gene expressions. The gene classifications tested are HP1BP3, CSDE1, and many more. With this data, Dr. Bettegowda was able to conclude that primary usage of CSF fluid for detecting medulloblastomas not only through gene analysis, but also through lipid extraction and metabolic expression analysis, is a way to identify medulloblastoma diagnosis. This can pave the way for further research on pre-screening methods not only for medulloblastomas, but also for many other neurological tumors that involve CSF fluid.
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