# Advancing the translatability of mouse models for cancer immunotherapy

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · 2020 · $720,801

## Abstract

One of greatest challenges in oncology is eradicating cancer once it has metastasized. Cancer immunotherapy
(IMT) with checkpoint blockade drugs like α-PD1 has shown remarkable sustained complete responses in a
subset of cancer patients. But even within sensitive tumor types such as melanoma, only around 25% of
patients respond. Many challenges remain to fully capitalize on existing and novel drugs that reactivate anti-
tumor immunity. There is, therefore, an urgent unmet need for mouse models that better reflect human cancer.
Our goal is to utilize the well characterized chemically-induced cutaneous squamous cell carcinoma (cSCC)
model to i) identify genetic features of tumors that establish IMT sensitivity, ii) define mechanisms and
biomarkers of innate and acquired α-PD-1 drug resistance iii) define mechanisms of cooperation between
αTGFβ and αPD1 therapy, and causes of failure. We will build on two novel and important observations that
we have made: First, that a new α-panTGFβ antibody is as effective as IMT and cooperates with αPD-1 to
double the IMT response rate, eliciting robust tumor rejection and sustained tumor immunity in the cSCC
model. Secondly, just as in human cancers, we find that response to IMT is higher in chemically-induced
cSCCs with high mutational single nucleotide variant (SNV) loads than those with low SNV load, including a
genetically engineered mouse model (GEMM). In Aim 1 we will address how αTGFβ therapy enhances αPD-1
responses, by investigating drug effects on tumor immune cell numbers and function. We will validate our
preliminary finding of Treg involvement in cooperativity between αPD1 and αTGFβ drugs using CyTO and MIBI
analysis. We will also investigate involvement of other immune cell types, particularly myeloid, that may
contribute to αTGFβ/αPD-1 drug cooperativity. In Aim 2, we will i
dentify tumor cell genetic properties that
determine IMT responses, and events driving development of IMT drug resistance, in a panel of independent
DMBA/TPA induced syngeneic primary cSCC lines driven by distinct chemically-induced mutations of Kras or
Hras. We will investigate effects of a) distinct Ras driver mutations b) SNV loads and neoantigen quality, and c)
miRNA and RNA transcriptome profiles, on α-PD-1 and/or αTGFβ responses, and we will extend our studies
into primary chemically induced sSCC, and validate the use of predictive biomarkers found in Aims 1 and 2 in
this more realistic and heterogeneous model of human cancer. Finally, in Aim 3, we will validate our preclinical
findings of mutational, transcriptomic and/or immune signatures predictive of IMT responses by interrogating
pre-treatment and post-treatment clinical HNSCC samples from αPD-1 responding versus non-responding
HNSCC patients under treatment at UCSF. By project completion, we will have validated a translational
model for IMT that may be utilized by others for novel IMT agent development, and for mechanistic studies that
will provide personalized tre...

## Key facts

- **NIH application ID:** 9841356
- **Project number:** 5R01CA210561-03
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
- **Principal Investigator:** ROSEMARY J AKHURST
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $720,801
- **Award type:** 5
- **Project period:** 2018-01-01 → 2022-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9841356

## Citation

> US National Institutes of Health, RePORTER application 9841356, Advancing the translatability of mouse models for cancer immunotherapy (5R01CA210561-03). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/9841356. Licensed CC0.

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