Related Experiment Video
Updated: Oct 8, 2025
Mimicking and Manipulating Pancreatic Acinar-to-Ductal Metaplasia in 3-dimensional Cell Culture
Published on: February 11, 2019
Loss of Rnf43 Accelerates Kras-Mediated Neoplasia and Remodels the Tumor Immune Microenvironment in Pancreatic
Abdel Nasser Hosein1, Gita Dangol2, Takashi Okumura2
1Department of Translational Molecular Pathology, Ahmad Center for Pancreatic Cancer Research, The University of Texas MD Anderson Cancer Center, Houston, Texas; Department of Internal Medicine, Division of Hematology and Oncology, The University of Texas Southwestern Medical Center, Dallas, Texas; Advocate Aurora Health, Vince Lombardi Cancer Clinic, Sheboygan, Wisconsin.
Background & Aims:
RNF43 is an E3 ubiquitin ligase that is recurrently mutated in pancreatic ductal adenocarcinoma (PDAC) and precursor cystic neoplasms of the pancreas. The impact of RNF43 mutations on PDAC is poorly understood and autochthonous models have not been characterized sufficiently. In this study, we describe a genetically engineered mouse model (GEMM) of PDAC with conditional expression of oncogenic Kras and deletion of the catalytic domain of Rnf43 in exocrine cells.
Methods:
We generated Ptf1a-Cre;LSL-KrasG12D;Rnf43flox/flox (KRC) and Ptf1a-Cre; LSL-KrasG12D (KC) mice and animal survival was assessed. KRC mice were sacrificed at 2 months, 4 months, and at moribund status followed by analysis of pancreata by single-cell RNA sequencing. Comparative analyses between moribund KRC and a moribund Kras/Tp53-driven PDAC GEMM (KPC) was performed. Cell lines were isolated from KRC and KC tumors and interrogated by cytokine array analyses, ATAC sequencing, and in vitro drug assays. KRC GEMMs were also treated with an anti-CTLA4 neutralizing antibody with treatment response measured by magnetic response imaging.
Results:
We demonstrate that KRC mice display a marked increase in incidence of high-grade cystic lesions of the pancreas and PDAC compared with KC. Importantly, KRC mice have a significantly decreased survival compared with KC mice. Using single-cell RNA sequencing, we demonstrated that KRC tumor progression is accompanied by a decrease in macrophages, as well as an increase in T and B lymphocytes, with evidence of increased immune checkpoint molecule expression and affinity maturation, respectively. This was in stark contrast to the tumor immune microenvironment observed in the KPC PDAC GEMM. Furthermore, expression of the chemokine CXCL5 was found to be specifically decreased in KRC cancer cells by means of epigenetic regulation and emerged as a putative candidate for mediating the unique KRC immune landscape.
Conclusions:
The KRC GEMM establishes RNF43 as a bona fide tumor suppressor gene in PDAC. This GEMM features a markedly different immune microenvironment compared with previously reported PDAC GEMMs and puts forth a rationale for an immunotherapy approach in this subset of PDAC cases.
More Related Videos
06:51Utilizing 18F-FDG PET/CT Imaging and Quantitative Histology to Measure Dynamic Changes in the Glucose Metabolism in Mouse Models of Lung Cancer
Published on: July 21, 2018
06:21Ultrasound-Guided Orthotopic Implantation of Murine Pancreatic Ductal Adenocarcinoma
Published on: November 19, 2019
Related Concept Videos
02:38The Ras Gene
Ras is a...
01:24Small GTPases - Ras and Rho
Three regulatory proteins control their activity:
03:03mTOR Signaling and Cancer Progression
The mTOR pathway or the...
02:23Abnormal Proliferation
01:20The Retinoblastoma Gene
The first-ever tumor suppressor gene called Rb was identified in retinoblastoma - a rare eye tumor in children. In inherited forms of the disease, a child inherits one defective copy of the Rb gene, which predisposes them to retinoblastoma. However,...
01:12Loss of Tumor Suppressor Gene Functions
When the tumor suppressor genes develop mutations or are lost, cells start growing out of control, leading to cancer. However, a single functional copy of the tumor suppressor gene is enough for the cells to maintain their normal functions and cell...