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Abstract Cholangiocarcinoma (CCA) is a highly aggressive and malignant tumor. In this study, the effect and molecular mechanism of nuclear enriched abundant transcript 1 (NEAT1) in CCA were elucidated. The expressions of NEAT1, microRNA‐186‐5p (miR‐186‐5p), and PTP4A1 were measured by quantitative real‐time PCR. The protein levels were measured by Western blotting. Kaplan–Meier analysis was performed to create survival curves. The interactions between NEAT1, miR‐186‐5p, and PTP4A1 were assessed through the dual luciferase reporter assay. Additionally, the cell proliferation, apoptosis, migration, and invasion were measured by colony formation, flow cytometry, the Transwell assay, and the wound healing assay, respectively. NEAT1 and PTP4A1 were significantly upregulated in CCA tissues and cells, but miR‐186‐5p was downregulated. NEAT1 expression was negatively correlated with the survival of CCA patients and has remarkable correlation with serum CA199 levels and lymph node metastasis. Besides, NEAT1 could act as a molecular sponge for miR‐186‐5p to upregulate PTP4A1 expression. More importantly, the knockdown of NEAT1 or overexpression of miR‐186‐5p inhibited the proliferation, migration and invasion of CCA cells, and the inhibition of miR‐186‐5p reversed the effects of the knockdown of NEAT1. In addition, NEAT1 could also activate the PI3K/AKT signaling pathway and regulate the epithelial‐mesenchymal transition (EMT) through the miR‐186‐5p/PTP4A1 axis. In conclusion, NEAT1 was involved in cell proliferation, migration and invasion in CCA, and the NEAT1/miR‐186‐5p/PTP4A1/PI3K/AKT axis indicated novel regulatory mechanisms and therapeutics for the treatment of CCA.

Objective To investigate the value of in vivo proton magnetic resonance spectroscopy (MRS) in the assessment of hepatocellular carcinoma (HCC) and monitor its metabolic change shortly after transcatheter arterial chemoembolization (TACE). Methods In this prospective study, 28 consecutive patients with large HCC (⩾3 cm in diameter) confirmed by fine needle aspiration biopsy were recruited. The 1H MRS of all hepatic lesions and some uninvolved liver parenchyma were performed with 1.51 whole body MR scanner. Among them, 15 cases were evaluated again about one week after TACE. The main metabolites such as choline and lipid before and after interventional therapy were measured to assess the early response of the tumor. Results The technical success rate of 1H MRS in liver was high (33/41, 80% ) , closely related to breath motion, location of lesion, and size of voxel. In spectra, the choline compound peak of HCC elevated compared with uninvolved liver parenchyma. After TACE, both the amplitude and the area of choline resonance peak significantly descended (choline-to-lipid ratios from 0. 352 ± 0. 080 to 0. 167 ± 0. 030, P = 0. 026; from 0. 205 ± 0. 060 to 0. 070 ± 0. 020, P =0. 042, respectively); yet lipid resonance peak ascended. Conclusions In vivo `H MRS is technically feasible for the evaluation of large focal hepatic lesions, however, the reproducibility and stability are not as good as routine MR scan. 1H MRS can monitor the early stage metabolic changes of HCC after TACE but limitation like quantification still exists. [ABSTRACT FROM AUTHOR]