Targeting the PI3K/AKT/mTOR pathway offer a promising therapeutic strategy for cholangiocarcinoma patients with high doublecortin-like kinase 1 expression.

Cholangiocarcinoma (CCA), characterized by high heterogeneity and extreme malignancy, has a poor prognosis. Doublecortin-like kinase 1 (DCLK1) promotes a variety of malignant cancers in their progression. Targeting DCLK1 or its associated regulatory pathways can prevent the generation and deterioration of several malignancies. However, the role of DCLK1 in CCA progression and its molecular mechanisms remain unknown. Therefore, we aimed to investigate whether and how DCLK1 contributes to CCA progression. The expression of DCLK1 in CCA patients was detected using Immunohistochemistry (IHC). We established DCLK1 knockout and DCLK1 overexpression cell lines for Colony Formation Assay and Transwell experiments to explore the tumor-promoting role of DCLK1. RT-PCR, Western blot and multiple fluorescent staining were used to assess the association between DCLK1 and epithelial-mesenchymal transition (EMT) markers. RNA sequencing and bioinformatics analysis were performed to identify the underlying mechanisms by which DCLK1 regulates CCA progression and the EMT program. DCLK1 was overexpressed in CCA tissues and was associated with poor prognosis. DCLK1 overexpression facilitated CCA cell invasion, migration, and proliferation, whereas DCLK1 knockdown reversed the malignant tendencies of CCA cells, which had been confirmed both in vivo and in vitro. Furthermore, we demonstrated that DCLK1 was substantially linked to the advancement of the EMT program, which included the overexpression of mesenchymal markers and the downregulation of epithelial markers. For the underlying mechanism, we proposed that the PI3K/AKT/mTOR pathway is the key process for the role of DCLK1 in tumor progression and the occurrence of the EMT program. When administered with LY294002, an inhibitor of the PI3K/AKT/mTOR pathway, the tumor's ability to proliferate, migrate, and invade was greatly suppressed, and the EMT process was generally reversed. DCLK1 facilitates the malignant biological behavior of CCA cells through the PI3K/AKT/mTOR pathway. In individuals with cholangiocarcinoma who express DCLK1 at high levels, inhibitors of the PI3K/AKT/mTOR signaling pathway may be an effective therapeutic approach.

Liang Z ，Ge Y ，Li J ，Bai Y ，Xiao Z ，Yan R ，An G ，Zhang D ... -  《-》

Knockdown of tripartite motif 59 (TRIM59) inhibits proliferation in cholangiocarcinoma via the PI3K/AKT/mTOR signalling pathway.

We analysed multiple microarray datasets in the Cancer Genome Atlas (TCGA) database and Gene Expression Omnibus (GEO) DataSets for messenger RNAs (mRNAs) whose expression is apparently increased in human cholangiocarcinoma (CCA) samples, compared with that in the adjacent normal biliary epithelial tissue. The results revealed that the expression of tripartite motif-containing 59 (TRIM59) was significantly increased in the CCA tissue samples. TRIM59 is a member of the tripartite motif (TRIM) protein family, which contains a highly conserved N-terminal-an interesting new gene (RING) domain regulating transcriptional factors and tumorigenesis. In the present study, we investigated the effects of TRIM59 expression on tumour growth in CCA. After analyzing the microarray datasets from the TCGA database and GEO DataSets, we screened out 291 target genes, which are significantly overexpressed in CCA tissues, and TRIM59 was one of them. The quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), Western blotting, and immunohistochemistry were performed to determine the expression of TRIM59 in CCA tissues (n = 65) and cell lines. Kaplan-Meier survival analysis was conducted to assess the prognosis of TRIM59 in patients with CCA. A specific siRNA (siRNA-1008) was used to inhibit the expression of TRIM59 in HCCC9810 and HUCCT1 cell lines. The effects of TRIM59 silencing on cell proliferation were assessed by the CCK-8, colony-formation, and EDU incorporation assays. Furthermore, the effects of TRIM59 knockdown on cell apoptosis and cell cycle were determined by flow cytometry. The in vivo effects were evaluated using a mouse tumorigenic model. Western blotting was also performed to verify the relationship between knockdown of TRIM59 and activation of the PI3K/AKT/mTOR pathway. TRIM59 was highly expressed in CCA tissues. The knockdown of TRIM59 obviously reduced the proliferation and colony formation abilities of CCA cells in vitro and in vivo. Furthermore, the cell apoptosis analysis results showed that TRIM59 silencing apparently promoted CCA cell apoptosis by the mitochondrial pathway. Our preliminary results indicate that the down-regulation of TRIM59 levels might restrict the PI3K/AKT/mTOR signalling pathway. Our study revealed that TRIM59 is up-regulated in CCA tissues and cell lines and promoted CCA cell proliferation, possibly by affecting the PI3K/AKT/mTOR signalling pathway.

Shen H ，Zhang J ，Zhang Y ，Feng Q ，Wang H ，Li G ，Jiang W ，Li X ... -  《-》

Antitumor activity of celastrol by inhibition of proliferation, invasion, and migration in cholangiocarcinoma via PTEN/PI3K/Akt pathway.

Zhu B ，Wei Y 《Cancer Medicine》

Increased activation of PI3K/AKT signaling pathway is associated with cholangiocarcinoma metastasis and PI3K/mTOR inhibition presents a possible therapeutic strategy.

Yothaisong S ，Dokduang H ，Techasen A ，Namwat N ，Yongvanit P ，Bhudhisawasdi V ，Puapairoj A ，Riggins GJ ，Loilome W ... -  《-》

A PLCB1-PI3K-AKT Signaling Axis Activates EMT to Promote Cholangiocarcinoma Progression.

As a member of the phospholipase family, phospholipase C beta 1 (PLCB1) is involved in phospholipid hydrolysis and is frequently upregulated in human cancer. However, little is known about the role of PLCB1 in cholangiocarcinoma (CCA). In this study, we uncover a role for PLCB1 in CCA progression and identify the underlying mechanisms. Both human CCA tissues and CCA cell lines expressed high levels of PLCB1. PLCB1 promoted tumor development and growth in various CCA mouse models, including transposon-based tumorigenesis models. PLCB1 activated PI3K/AKT signaling to induce CCA cells to undergo epithelial-to-mesenchymal transition (EMT). Mechanistically, PABPC1 interacted with PLCB1 and PI3K to amplify PLCB1-mediated EMT via PI3K/AKT/GSK3β/Snail signaling. Ectopic PLCB1 induced resistance to treatment with gemcitabine combined with cisplatin, which could be reversed by the AKT inhibitor MK2206. PLCB1 expression was regulated by miR-26b-5p through direct interaction with PLCB1 3'UTR. Collectively, these data identify a PLCB1-PI3K-AKT signaling axis vital for CCA development and EMT, suggesting that AKT can be used as a therapeutic target to overcome chemotherapy resistance in CCA patients with high PLCB1 expression. SIGNIFICANCE: PLCB1 functions as an oncogenic driver in cholangiocarcinoma development that confers an actionable therapeutic vulnerability to AKT inhibition.

Liang S ，Guo H ，Ma K ，Li X ，Wu D ，Wang Y ，Wang W ，Zhang S ，Cui Y ，Liu Y ，Sun L ，Zhang B ，Xin M ，Zhang N ，Zhou H ，Liu Y ，Wang J ，Liu L ... -  《-》