Long noncoding RNA Regulating ImMune Escape regulates mixed lineage leukaemia protein-1-H3K4me3-mediated immune escape in oesophageal squamous cell carcinoma.

BACKGROUND: Predictive biomarkers for oesophageal squamous cell carcinoma (ESCC) immunotherapy are lacking, and immunotherapy resistance remains to be addressed. The role of long noncoding RNA (lncRNA) in ESCC immune escape and immunotherapy resistance remains to be elucidated. METHODS: The tumour-associated macrophage-upregulated lncRNAs and the exosomal lncRNAs highly expressed in ESCC immunotherapy nonresponders were identified by lncRNA sequencing and polymerase chain reaction assays. CRISPR-Cas9 was used to explore the functional roles of the lncRNA. RNA pull-down, MS2-tagged RNA affinity purification (MS2-TRAP) and RNA-binding protein immunoprecipitation (RIP) were performed to identify lncRNA-associated proteins and related mechanisms. In vivo, the humanized PBMC (hu-PBMC) mouse model was established to assess the therapeutic responses of specific lncRNA inhibitors and their combination with programmed cell death protein 1 (PD-1) monoclonal antibody (mAb). Single-cell sequencing, flow cytometry, and multiplex fluorescent immunohistochemistry were used to analyze immune cells infiltrating the tumour microenvironment. RESULTS: We identified a lncRNA that is involved in tumour immune evasion and immunotherapy resistance. High LINC02096 (RIME) expression in plasma exosomes correlates with a reduced response to PD-1 mAb treatment and poor prognosis. Mechanistically, RIME binds to mixed lineage leukaemia protein-1 (MLL1) and prevents ankyrin repeat and SOCS box containing 2 (ASB2)-mediated MLL1 ubiquitination, improving the stability of MLL1. RIME-MLL1 increases H3K4me3 levels in the promoter regions of programmed death-ligand 1 (PD-L1) and indoleamine 2,3-dioxygenase 1 (IDO-1), constitutively increasing the expression of PD-L1/IDO-1 in tumour cells and inhibiting CD8+ T cells infiltration and activation. RIME depletion in huPBMC-NOG mice significantly represses tumour development and improves the effectiveness of PD-1 mAb treatment by activating T-cell-mediated antitumour immunity. CONCLUSIONS: This study reveals that the RIME-MLL1-H3K4me3 axis plays a critical role in tumour immunosuppression. Moreover, RIME appears to be a potential prognostic biomarker for immunotherapy and developing drugs that target RIME may be a new therapeutic strategy that overcomes immunotherapy resistance and benefits patients with ESCC.

Which is the best combination of surgery for hepatocellular carcinoma with hepatic/portal vein thrombosis in China: a network meta-analysis of randomized controlled trials.

PURPOSE: To assess the efficacy and safety of different perioperative regimens using network meta-analysis for hepatocellular carcinoma (HCC) with hepatic/portal vein thrombosis. The interested modalities included neoadjuvant three-dimensional conformal radiotherapy (3D-CRT), post-operative intensity modulated radiation therapy (IMRT). post-operative transarterial chemoembolization (TACE) and surgery alone. METHODS: PubMed and Cochrane Library electronic databases were systematically searched for eligible studies published up to November 2020. Data related to treatment efficacy including overall survival (OS), and disease-free survival (DFS) were extracted and compared using a Bayesian approach. Adverse events (AEs) were assessed and compared. RESULTS: Four studies published between 2005 and 2020 involving a total of 422 patients were enrolled in this network meta-analysis. The comparison showed that surgery with IMRT ranked relatively higher in prolonging OS in advanced HCC patients, followed by neoadjuvant 3DCRT and surgery plus TACE. Postoperative IMRT appeared better choice in terms of DFS. The rate of AEs did not significantly differ. CONCLUSION: Adjuvant IMRT showed more favorable treatment responses compared with other regimens in HCC patients with hepatic/portal vein thrombosis.

Loperamide, an antidiarrhea drug, has antitumor activity by inducing cell apoptosis.

Loperamide, an antidiarrhea drug, is a peripheral opiate agonist. Some other opiate agonists have been shown to promote cell apoptosis. In this research, we studied the apoptosis-inducing and cytotoxic activities of loperamide. MTT assay was used to determine its cytotoxicity on nine established human tumor cell lines. Cell apoptosis was detected by flow cytometry. Hypodiploid cells and cell cycles were analyzed by propidium iodide (PI) staining, while early apoptotic cells were detected by annexin V-FITC/PI staining. It was found that loperamide could inhibit the proliferation of the tested tumor cell lines. The IC50 values for SMMC7721, MCF7, SPC-A1, SKOV3-DDP, H460, HepG2, SGC7901, U2OS, and ACHN cells were 24.2±2.1 µM, 23.6±2.5 µM, 25.9±3.1 µM, 27.1±2.5 µM, 41.4±2.1 µM, 23.7±1.3 µM, 35.4±3.5 µM, 11.8±2.8 µM, and 28.5±3.4 µM, respectively. Loperamide was more effective to the human osteosarcoma U2OS cells with an IC50 value of 11.8±2.8 µM. Meanwhile, it could induce cell apoptosis and cause G2/M-phase cell cycle arrest. The apoptotic cells could be found when treating with loperamide for 6h and most of them belonged to early apoptosis. In loperamide-treated cells, activation of caspase-3 was found, namely that caspase-3 was involved in the loperamide-induced apoptosis. The results of these studies indicate that loperamide is a potential antitumor agent. To our knowledge, this is the first report on antitumor activity of loperamide.