Abstract 2001: Krupple like factor 10 modulates stem cell phenotype of pancreatic adenocarcinoma via transcriptional regulation of Notch signal pathway
Authors: Tsai Yi-Chih , Chen Su-Liang , Peng Shu-Ling , Cheng Kuang-Hung , Jiang Shih-Sheng , Chuang Shuang-En , Hui-Ju Ch'ang 
Published: July 2021

Abstract
Background: Pancreatic adenocarcinoma (PDAC) is known for its deregulated TGFβ signal pathway. Therapeutic strategy targeting TGFβ is controversial due to the dual role of TGFβ with anti-proliferation in early phase and pro-metastatic in late phase of cancer progression. KLF10, an early response gene of TGFβ, positively feedback the antiproliferative effect in cancer. Recent studies revealed KLF10 expression were suppressed epigenetically in various cancers including PDAC. In contrary to TGFβ, KLF10 transcriptionally suppress Slug and Sirtuin 6 to prevent metastasis in advanced PDAC. The role of KLF10 in regulating tumorigenesis and stem cell phenotype is still unknown.
Materials and Methods: From 105 patients of resectable PDAC, KLF10 expression level was evaluated to be reduced in 62% of tumor specimens. Low KLF10 expression correlated with larger tumor size and rapid loco-regional recurrence. In murine model of Kras mutation (KC mice), additional depletion of KLF10 induced 57% of PDAC compared to 0% at 18 to 24 wk of age. PDAC cells were genetically manipulated with KLF10mRNA silencing (PDACshKLF10) or inducible overexpression (PDACoeKLF10). Using limiting dilution assay of tumor growth, and orthotopic tumor implantation, we found higher tumorigenic ability of PDACshKlf10 compared to that of wild type. The stem cell phenotypes of PDACshKLF10 and PDACoeKLF10 were confirmed by sphere formation assay and FACS analysis of surface markers including CD24/CD44, ESA/c-Met, CD47 and CD133.
Results: Notch signal pathway was found to be significantly enhanced from microarray analysis of wild type versus PDACshKLF10 cells. The increased Notch signal molecules were confirmed in RNA and protein level in genetically manipulated PDAC cells as well as clinical tissue specimens. Using Chip-PCR and luciferase promoter assay, KLF10 was demonstrated to bind to the promoter of Notch receptor 1, 3, and 4. DAPT (N-[N-(3,5-Difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester), a Notch inhibitor, suppressed in vitro spheroid formation, cell surface expression of stem cell markers, and tumor growth of PDACshKLF10 in orthotopic murine model. We conclude that KLF10 modulates stem cell phenotype of PDAC by transcriptionally suppressing Notch signal pathway. Loss of KLF10 in PDAC patients leads to Notch signal activation, development of stem cell phenotype and tumor progression. Notch inhibition may reverse malignant growth of PDAC with reduced KLF10 expression.
Conflict of interest statement: nothing to declare
Citation Format: Yi-Chih Tsai, Su-Liang Chen, Shu-Ling Peng, Kuang-Hung Cheng, Shih-Sheng Jiang, Shuang-En Chuang, Ch'ang Hui-Ju. Krupple like factor 10 modulates stem cell phenotype of pancreatic adenocarcinoma via transcriptional regulation of Notch signal pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2001.