Targeting the NF-kB Pathway to Treat NF1-Deficient Tumors
Abstract
Neurofibromatosis type 1 (NF1) is a tumor-predisposing genetic condition with an incidence rate of 1 in 3,000 individuals. While there are several symptoms that individuals with NF1 may experience, one of the most common is the formation of benign tumors known as plexiform neurofibromas (PNs). In around 12% of individuals with NF1, PNs have the potential to transform into malignant peripheral nerve sheath tumors (MPNSTs), which are often unresectable due to their location and resistant to most therapies available; as a result, MPNSTs are often fatal. Both PNs and MPNSTs are comprised of Schwann cells (SCs), the major glial cell in the peripheral nervous system. While there are no therapeutic options for MPNSTs, there is only one FDA-approved therapy for treating PNs, the MEK1/2 inhibitor Selumetinib. While Selumetinib has been successful in treating PNs in children and adolescents with NF1, there are many unknowns surrounding long-term treatment with MEK inhibitors, including concerns regarding side effects and resistance. For these reasons, there still exists an unmet clinical need for identifying new therapeutic strategies for treating individuals with NF1. To address this need, our laboratory has chosen to focus on identifying differences in the SCs that make up a NF1 patient’s normal tissue and PN tissue. To do this, we used a panel of pairs of cell lines derived from patients or generated in our laboratory using CRISPR technology that were either like a patient’s normal tissue (missing one copy of the NF1 gene) or like a patient’s PN tissue (missing two copies of the NF1 gene) to identify altered signaling networks. We did this by measuring changes in the global cellular landscape between each pair of cells, which allowed us to identify a plethora of potential targets involved in a variety of cellular processes. We performed comparison analyses between our two matched sets of patient-derived SC lines to identify overlapping hits, and in doing so we were able to refine our list of potential targets. Our proposal focuses on investigating one signaling network identified through these analyses: the NF-kappaB pathway. Within this network, we have identified multiple targets that we will be exploring as potential therapeutic targets or biomarkers in treating NF1-deficient SCs like those found in PNs and MPNSTs. We have already demonstrated the therapeutic potential of targeting some of these targets with drugs, though this was performed on cell lines we used in our initial study. We will confirm that inhibition of these targets decreases the viability of NF1-deficient SCs in new pairs of NF1-deficient SC lines that we have generated using CRISPR-based gene editing strategies; we will also test drugs against other potential targets in these cell lines. We will measure cell viability as well as proteins involved in the cell death process known as apoptosis. We will also measure changes in proteins downstream of these targets to determine the impact of targeting NF-kappaB on other signaling networks. All the therapeutics tested that result in reduced viability of NF1-deficient SCs will also be tested in combination with the FDA-approved MEK inhibitor Selumetinib. We then want to test our successful inhibitors in MPNST-derived cell lines, as some studies have suggested that NF-kappaB is increased in MPNSTs prior to or after treatment with Selumetinib. We plan to test our inhibitors as both single agents and in combination with Selumetinib and measure proteins involved in cell death in addition to measuring viability. Finally, we will measure genes regulated by the NF-kappaB pathway, as transcription is anticipated to be altered due to target knockdown, and we will quantify gene expression, as this could reveal to us novel biomarkers for treating NF1. Any potential biomarkers will be measured in samples of PNs collected from patients to confirm their expression. The work we are proposing has the po
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 04, 2024
- Source ID
- HT94252310831
Entities
People
- Stephanie Bouley
Organizations
- Massachusetts General Hospital
- United States Army