Dataset Information

APKCι promotes gallbladder cancer tumorigenesis and gemcitabine resistance by competing with Nrf2 for binding to Keap1.

ABSTRACT: Gallbladder cancer (GBC) is a highly malignant bile duct cancer with poor prognosis characterized by its insensitivity to chemotherapy. Emerging evidence indicates that cytoprotective antioxidation is involved in drug resistance of various cancers; however, the underlying molecular mechanisms remain obscure. Here, we demonstrated that atypical protein kinase Cι (aPKCι) mediated reactive oxygen species (ROS) inhibition in a kinase-independent manner, which played a crucial role in tumorigenesis and chemoresistance. Mechanistically, we found that aPKCι facilitated nuclear factor erythroid 2-related factor 2 (Nrf2) accumulation, nuclear translocation and activated its target genes by competing with Nrf2 for binding to Kelch-like ECH-associated protein 1 (Keap1) through a highly conserved DLL motif. In addition, the aPKCι-Keap1 interaction was required for antioxidant effect, cell growth and gemcitabine resistance in GBC. Importantly, we further confirmed that aPKCι was frequently upregulated and correlated with poor prognosis in patients with GBC. Collectively, our findings suggested that aPKCι positively modulated the Keap1-Nrf2 pathway to enhance GBC growth and gemcitabine resistance, implying that the aPKCι-Keap1-Nrf2 axis may be a potential approach to overcome the drug resistance for the treatment of GBC.

SUBMITTER: Tian L

PROVIDER: S-EPMC6395946 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature

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aPKCι promotes gallbladder cancer tumorigenesis and gemcitabine resistance by competing with Nrf2 for binding to Keap1.

Tian Li L Lu Yun Y Yang Tao T Deng Zhengdong Z Xu Lei L Yao Wei W Ma Chaoqun C Li Xiangyu X Zhang Jian J Liu Yan Y Wang Jianming J

Redox biology 20190221

Gallbladder cancer (GBC) is a highly malignant bile duct cancer with poor prognosis characterized by its insensitivity to chemotherapy. Emerging evidence indicates that cytoprotective antioxidation is involved in drug resistance of various cancers; however, the underlying molecular mechanisms remain obscure. Here, we demonstrated that atypical protein kinase Cι (aPKCι) mediated reactive oxygen species (ROS) inhibition in a kinase-independent manner, which played a crucial role in tumorigenesis a ...[more]

PMID: 30822690

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Project description:BackgroundCancer-associated fibroblasts (CAFs) are key components of tumor microenvironment and have been identified to be involved in modulating drug resistance in cancers by secreting molecules. Pancreatic cancer (PC) is a leading cause of cancer mortality with high aggressiveness. Gemcitabine (GEM) is one of primary antineoplastic drugs for PC. Collagen XVII (COL17A1) expression was found to be upregulated in GEM-resistant CAFs. Here, this study focused on investigating whether CAFs affected GEM resistance in PC by secreting COL17A1 and its associated mechanisms.MethodsIn total, 60 newly diagnosed PC patients only with GEM-based chemotherapy were recruited. Normal fibroblasts (NFs) and CAFs were isolated using fresh normal and resistant PC tissues. Human pancreatic duct epithelial (HPDE) cells were used for functional analyses. Levels of COL17A1 and Actinin Alpha 4 (ACTN4) were measured by using qRT-PCR and western blotting. Functional analyses were conducted using MTT, 5-ethynyl-2'-deoxyuridine, transwell, and sphere formation assays, respectively. The interaction between COL17A1 and ACTN4 was analyzed by Co-immunoprecipitation and immunofluorescence assays. Animal models were established for in vivo analysis.ResultsCAF incubation promoted GEM resistance and enhanced the proliferation, invasion and stemness in GEM-resistant PC cells. COL17A1 was highly expressed in resistant CAFs and GEM-resistant PC cells, and CAF incubation could increase COL17A1 expression in resistant PC cells. Moreover, COL17A1 silencing in GEM-resistant PC cells or the incubation of COL17A1-decreased CAF with GEM-resistant PC cells could suppress GEM resistance and cell oncogenic phenotype progression. Mechanistically, COL17A1 interacted with ACTN4 protein, and the anticancer effects mediated by COL17A1-decreased CAFs in resistant PC cells were reversed by ACTN4 overexpression. In vivo assay also showed that COL17A1-decreased CAFs suppressed the growth and GEM resistance in PC by ACTN4.ConclusionCAFs-derived COL17A1 promoted GEM resistance and tumorigenesis in PC by interacting with ACTN4, suggesting a new method for overcoming GEM resistance in PC.

Dataset Information

APKCι promotes gallbladder cancer tumorigenesis and gemcitabine resistance by competing with Nrf2 for binding to Keap1.

Publications

aPKCι promotes gallbladder cancer tumorigenesis and gemcitabine resistance by competing with Nrf2 for binding to Keap1.

Similar Datasets

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