# Increasing NF1 Expression as a Treatment for NF1 Haploinsufficiency

> **NIH NIH R43** · INFIXION BIOSCIENCE, INC. · 2021 · $53,803

## Abstract

Project Abstract
Haploinsufficiency plays a crucial role in Neurofibromatosis (NF1), an autosomal dominant genetic disorder
impacting over 120,000 individuals in the United States. Current therapeutic approaches focus on specific
components of NF1 signaling, for example inhibiting MEK signaling pathways in tumors, thus failing to address
the broad range of signaling and symptoms associated with NF1. Given that NF1 is characterized by both
autosomal dominance and haploinsufficiency (lack of normal protein), upregulating protein expression of the
remaining wild-type NF1 allele has the ability to compensate for loss of function from the mutant allele, thus
alleviating a broad range of NF1 symptoms and overall disease progression. Infixion proposes to build a
luciferase reporting assay to evaluate NF1 expression against known drugs, including 50+ compounds, across
six drug classes, already identified by Infixion to correlate with increased NF1 expression. By confirming that
these candidate drugs activate NF1 transcription, increase NF1 protein expression, and normalize Ras
pathway signaling in NF1 +/- Schwann cells, and by further screening libraries of known drugs for increased
NF1 expression, we propose a novel path of NF1 drug discovery that will impact a broad range of NF1 patients
and symptoms, in a preventative manner, and without regard to the wide spectrum of NF1 genetic mutations.
Research Background. Increasing NF1 expression via transfection reverses abnormal Ras activation
resulting from NF1 loss (Wallis, et al. 2018). Transcriptional activation in other genetic conditions such as
Willams-Beuren Syndrome, and Supravalvular Aortic Stenosis compensates for haploinsufficiency (Giordano,
et al. 2012). Lastly, overcoming haploinsufficiency in another autosomal dominant condition (Sim1 induced
obesity; mouse model) was recently shown using a Crispr/dCas9 transcriptional activator (Ahituv, et al. 2019).
Specific Aims. 1) Construct a luciferase reporter assay engineered into the endogenous NF1 gene of a well
characterized, publically available, immortalized NF1 +/- Schwann cell line (Wallace et al. 2016; data published
at Synapse.org). Validate assay using a viral transcription factor developed by Infixion using Crispr/dCas9 to
upregulate NF1. 2) Deploy this NF1 luciferase reporter assay to screen 50+ known drugs shown by Infixion to
correlate with increased NF1 expression across various cell/tissue types. Next, use this validated luciferase
reporter to screen a 13,000+ compound repurposing library of known drugs available from Scripps Research
Institute (known as ReFrame). 3) The top hits from Aim 2 screens will be evaluated, utilizing both immortalized
and iPSC derived NF1+/- Schwann cells, for the following: a) ability to induce NF1 mRNA and protein
expression, using qPCR and Westerns, b) the impact on Ras signaling (pERK, ELK-1, AKT, etc.) utilizing a
targeted quantitative mass spec proteomics assay, c) their broader impact on gene expression...

## Key facts

- **NIH application ID:** 10408303
- **Project number:** 3R43NS117234-02S1
- **Recipient organization:** INFIXION BIOSCIENCE, INC.
- **Principal Investigator:** Clifford Dustin Rubinstein
- **Activity code:** R43 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $53,803
- **Award type:** 3
- **Project period:** 2021-07-15 → 2022-09-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10408303

## Citation

> US National Institutes of Health, RePORTER application 10408303, Increasing NF1 Expression as a Treatment for NF1 Haploinsufficiency (3R43NS117234-02S1). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10408303. Licensed CC0.

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