No abstract

Cholangiocarcinoma (CCA) is the second most common primary hepatic malignancy and associated with poor prognosis. Lack of therapeutic methods for CCA and insensitivity of targeted therapy and immunotherapy make its treatment challenging. NUF2, a component of Ndc80 kinetochore complex, is implicated in the initiation and development of multiple cancers. However, the role and mechanism of NUF2 in CCA is still unclear. In this research, we investigated the biological processes and underlying mechanisms of NUF2 in CCA. We discovered that the expression of NUF2 was upregulated in CCA and negatively correlated with prognosis. Changes in NUF2 levels had an impact on cell proliferation and migration. Moreover, NUF2 functioned as an oncogene to promote the progression of CCA through p38/MAPK signaling by inhibiting p62 binding of TFR1 and affecting its autophagic degradation. In addition, TFR1 promoted CCA progression and Kaplan-Meier analyses uncovered patients with high expression of TFR1 was associated with the poor survival. In conclusion, our study demonstrated that NUF2 promoted CCA progression by regulating TFR1 protein degradation, and the NUF2/TFR1/MAPK axis could be an excellent therapeutic target for CCA.

BackgroundCholangiocarcinoma (CCA) remains one of the most lethal malignancies with an increasing incidence globally. Through whole-exome sequencing of 67 CCA tissues, we identified new mutated genes in CCA, including MACF1, METTL14, ROBO1, and so on. The study was designed to explore the effects and mechanism of ROBO1 wild type (ROBO1WT) and ROBO1E280* mutation on the progression of CCA.MethodsWhole-exome sequencing was performed to identify novel mutations in CCAs. In vitro and in vivo experiments were used to examine the function and mechanism of ROBO1WT and ROBO1E280* in cholangiocarcinoma. A tissue microarray including 190 CCA patients and subsequent analyses were performed to indicate the clinical significance of ROBO1.ResultsThrough whole-exome sequencing, we identified a novel CCA-related mutation, ROBO1E280*. ROBO1 was downregulated in CCA tissues, and the downregulation of ROBO1 was significantly correlated with poor prognosis. ROBO1WT suppressed the proliferation and angiogenesis of CCA in vitro and in vivo, while ROBO1E280* lost the inhibitory effects. Mechanically, ROBO1E280* translocated from the cytomembrane to the cytoplasm and interrupted the interaction between SLIT2 and ROBO1. We identified OLFML3 as a potential target of ROBO1 by conducting RNA-Seq assays. OLFML3 expression was downregulated by ROBO1WT and recovered by ROBO1E280*. Functionally, the silence of OLFML3 inhibited CCA proliferation and angiogenesis and was sufficient to repress the loss-of-function role of ROBO1E280*.ConclusionsThese results suggest that ROBO1 may act as a tumor suppressor and potential prognostic marker for CCA. ROBO1E280* mutation is a loss-of-function mutation, and it might serve as a candidate therapeutic target for CCA patients.

Background Cholangiocarcinoma (CHOL) is the second most common primary hepatic malignant tumor, following hepatocellular carcinoma (HCC). CHOL is highly aggressive and heterogeneous resulting in poor prognosis. The diagnosis and prognosis of CHOL has not improved in the past decade. Acyl-CoA synthetase long-chain family member 4 (ACSL4) is reported to be associated with tumors, however, its role in CHOL has not been revealed. This study is mainly for exploring the prognostic values and potential function of ACSL4 in CHOL. Methods We investigated the expression level and prognostic value of ACSL4 in CHOL based on The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets. TIMER2.0, TISIDB and CIBERSORT databases were utilized to assess the associations between ACSL4 and immune infiltration cells in CHOL. Single-cell sequencing data from GSE138709 was analyzed to study the expression of ACSL4 in different types of cells. ACSL4 co-expressed genes were analyzed by Linkedomics. Additionally, Western Blot, qPCR, EdU assay, CCK8 assay, transwell assay and wound healing assay were performed to further confirm the roles of ACSL4 in the pathogenesis of CHOL. Results We found that the level of ACSL4 was higher in CHOL and it was correlated with the diagnosis and prognosis of CHOL patients. Then, we observed that the infiltration level of immune cells was related to the level of ACSL4 in CHOL. Moreover, ACSL4 and its co-expressed genes were mainly enriched in metabolism-related pathway and ACSL4 is also a key pro-ferroptosis gene in CHOL. Finally, knockdown of ACSL4 could reverse the tumor-promoting effect of ACSL4 in CHOL. Conclusions The current findings demonstrated ACSL4 may as a novel biomarker for CHOL patients, which might regulate immune microenvironment and metabolism resulting in poor prognosis.