Title

Loss of Rnf43 accelerates Kras-mediated neoplasia and remodels the tumor immune microenvironment in pancreatic adenocarcinoma

Authors

Abdel Nasser Hosein, Advocate Aurora HealthFollow
Gita Dangol, Department of Translational Molecular Pathology, Ahmad Center for Pancreatic Cancer Research, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
Takashi Okumura, Department of Translational Molecular Pathology, Ahmad Center for Pancreatic Cancer Research, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
Jason Roszik, Department of Melanoma Medical Oncology Research, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
Kimal Rajapakshe, Department of Translational Molecular Pathology, Ahmad Center for Pancreatic Cancer Research, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
Megan Siemann, Department of Translational Molecular Pathology, Ahmad Center for Pancreatic Cancer Research, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
Mohamed Zaid, Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
Bidyut Ghosh, Department of Translational Molecular Pathology, Ahmad Center for Pancreatic Cancer Research, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
Maria Monberg, Department of Translational Molecular Pathology, Ahmad Center for Pancreatic Cancer Research, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
Paola A. Guerrero, Department of Translational Molecular Pathology, Ahmad Center for Pancreatic Cancer Research, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
Aatur Singhi, Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.
Cara L. Haymaker, Department of Translational Molecular Pathology, Ahmad Center for Pancreatic Cancer Research, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
Hans Clevers, Oncode Institute, Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences, University Medical Center Utrecht and Princess Maxima Center, Utrecht, the Netherlands.
Lotfi Abou-Elkacem, Department of Translational Molecular Pathology, Ahmad Center for Pancreatic Cancer Research, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
Sonja M. Woermann, Department of Translational Molecular Pathology, Ahmad Center for Pancreatic Cancer Research, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
Anirban Maitra, Department of Translational Molecular Pathology, Ahmad Center for Pancreatic Cancer Research, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA. Electronic address: amaitra@mdanderson.org.

Affiliations

Vince Lombardi Cancer Clinic - Sheboygan

Abstract

Background: 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 sufficiently characterized. 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 (scRNAseq). 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-seq 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 to KC. Importantly, KRC mice have a significantly decreased survival compared to KC mice. By use of scRNAseq 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 to previously reported PDAC GEMMs and puts forth a rationale for an immunotherapy approach in this subset of PDAC cases.

Document Type

Article

PubMed ID

34973294

Link to Full Text

 

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