# A novel pathway to overcome resistance to immunotherapy in melanoma

> **NIH NIH R01** · NORTHWESTERN UNIVERSITY · 2024 · $366,000

## Abstract

Project Summary/Abstract
Despite the progress in the treatment of advanced melanoma brought by the approval and use of immune
checkpoint inhibitors (ICIs), most patients are resistant to therapy initially or respond but then relapse. A critical
pathway that controls responses to ICIs is regulated by interferon-gamma (IFNγ). While IFNγ signaling increases
expression of immunostimulatory genes (IStGs) required for response to ICIs, it also induces the expression of
immunosuppressive genes (ISpGs) that support tumor immune escape and promote resistance to ICIs. This
dual and opposing role of IFNγ signaling supports the need to identify an approach to inhibit expression of ISpGs,
without limiting the expression of IStGs to improve the response rates to ICI-based therapies. We have identified
a new transcriptional regulatory function for the Unc-51-like kinase 1 (ULK1) downstream of the IFNγ receptor,
independent of its autophagy-related function. We have shown that, in malignant melanoma cells, inhibition of
ULK1 represses IFNγ-induced transcription of ISpGs, without affecting the expression of IStGs, both in vitro and
in vivo. Importantly, we have found that ULK1 interacts with IRF1 in the nuclear compartment of melanoma cells
and show that inhibition of ULK1 kinase activity reduces the binding of IRF1 to ISpG’s promoter region, but not
to IStGs. Remarkably, high levels of ULK1 correlate with poor survival and with an immunosuppressive tumor
microenvironment (TME) in melanoma patients. Moreover, in preliminary studies we show that drug-targeted
inhibition of ULK1 with anti-PD-1 (αPD-1) therapy induces significant increases in the percentages of IFNγ and
perforin producing CD8+ T and natural killer (NK) cells and reduction in the frequency of Tregs compared to αPD-
1 treatment alone in co-culture assays using B16 melanoma cells and pmel-1 splenocytes. The goal of this
project is to determine if blocking ULK1 will limit IFNγ-induced immunosuppressive effects and promote an
immunostimulatory TME, overcoming resistance to ICIs in melanoma. Aim 1 will determine the mechanism by
which ULK1 mediates the immunosuppressive function of IFNγ in melanoma cells. It includes generation of
specific CRISPR knockout (KO) cells, and studies to determine the role of IFNγ-induced ULK1-mediated
phosphorylation of IRF1 in melanoma cells. Aim 2 will determine the direct role of ULK1 in immune cell function
against melanoma and in response to ICIs in vivo using conditional Ulk1 KO mice. Additionally, we will use
CRISPR/Cas9 gene editing to specifically target ULK1 in primary human CD8+ T cells and study its role in
regulation of signaling cascades, gene transcription, and CD8+ T cell activity against melanoma. Aim 3 will
determine the role of ULK1 in ICI-resistant melanoma models. We will determine the effects of genetic or
pharmacological inhibition of ULK1 in response to ICIs in vivo. Additionally, we will correlate the expression of
ULK1 and IRF1 proteins in melanoma pa...

## Key facts

- **NIH application ID:** 10976865
- **Project number:** 1R01CA285876-01A1
- **Recipient organization:** NORTHWESTERN UNIVERSITY
- **Principal Investigator:** Diana Nora Vaz Saleiro
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $366,000
- **Award type:** 1
- **Project period:** 2024-07-01 → 2029-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10976865

## Citation

> US National Institutes of Health, RePORTER application 10976865, A novel pathway to overcome resistance to immunotherapy in melanoma (1R01CA285876-01A1). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10976865. Licensed CC0.

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