CRISPR/Cas9-based liver-derived reporter cells for screening of mPGES-1 inhibitors

mPGES-1 is a terminal rate-limiting enzyme responsible for inflammation-induced PGE2 production. The inhibition of mPGES-1 has been considered as a safe and effective target for the treatment of inflammation and cancer. However, a specific, efficient, and simple method for high-throughput screening of mPGES-1 inhibitors is still lacking. In this study, we developed a fluorescence imaging strategy to monitor the expression of mPGES-1 via CRISPR/Cas9 knock-in system. Immunofluorescence colocalisation, Sanger sequencing, RNAi, and IL-1β treatment all confirmed the successful construction of mPGES-1 reporter cells. The fluorescence signal intensity of the reporter cells treated with four conventional mPGES-1 inhibitors was considerably attenuated via flow cytometry and fluorescent microplate reader, demonstrating that the reporter cells can be used as an efficient and convenient means for screening and optimising mPGES-1 inhibitors. Moreover, it provides a new technical support for the development of targeted small molecule compounds for anti-inflammatory and tumour therapy

Expression of the RIP-1 Gene and its Role in Growth and Invasion of Human Gallbladder Carcinoma

Background and Aim: Receptor interacting protein(RIP)-1 is thought to have a significant role in inflammation signaling pathways; however, the role of RIP-1 in malignant tumors is largely unknown. Methods: The present study examined the functions and underlying mechanisms of RIP-1 in gallbladder cancer in vitro and in vivo. In this study we determined the expression and role of RIP-1 in 60 clinical specimens from patients with gallbladder cancer and 3 gallbladder cancer cell lines. Using siRNA targeting RIP-1, plasmid vectors (phU6-EGFP-puro/siRIP-1) were constructed and transfected into the gallbladder cells to characterize the biological effect of RIP-1. Results: In vitro experiments indicated that silencing of RIP-1 in NOZ cells significantly suppressed growth and invasion. Furthermore, silencing of RIP-1 affected the RIP1-NF-κB/c-jun(AP-1)-VEGF-C pathways in NOZ cells. Silencing of RIP-1 in vivo inhibited tumor growth in a NOZ cell subcutaneous xenograft model. Immunohistochemstry analysis of the tumor in thesubcutaneous xenograft model also suggested that RIP-1 mediates the expression of VEGF-C. Conclusion: We have elucidated therelationship between RIP-1 overexpression and the growth and invasion of gallbladder cancer from clinical specimens using a xenograft model. We provide evidence that a reduction in the expression of RIP-1 in gallbladder cancer cells can exert inhibitory effects on the ability of cells to grow and invade in vitro. Thus, targeting RIP-1may be useful in the treatment of gallbladder cancer

2,5-dimethylcelecoxib alleviated NK and T-cell exhaustion in hepatocellular carcinoma via the gastrointestinal microbiota-AMPK-mTOR axis

Background 2,5-dimethylcelecoxib (DMC), a derivative of celecoxib, is an inhibitor of microsomal prostaglandin E synthase-1 (mPGES-1). Our previous studies have demonstrated that DMC inhibits the expression of programmed death-ligand 1 on hepatocellular carcinoma (HCC) cells to prevent tumor progression. However, the effect and mechanism of DMC on HCC infiltrating immune cells remain unclear.Methods In this study, single-cell-based high-dimensional mass cytometry was performed on the tumor microenvironment of HCC mice treated with DMC, celecoxib and MK-886 (a known mPGES-1 inhibitor). Moreover, 16S ribosomal RNA sequencing was employed to analyze how DMC improved the tumor microenvironment of HCC by remodeling the gastrointestinal microflora.Results We found that (1) DMC significantly inhibited the growth of HCC and improved the prognosis of the mice, and this depended on the stronger antitumor activity of natural killer (NK) and T cells; (2) compared with celecoxib and MK-886, DMC significantly enhanced the cytotoxic and stem-like potential, and inhibited exhaustion of NK and T cells; (3) mechanistically, DMC inhibited the expression of programmed cell death protein-1 and upregulated interferon-γ expression of NK and T cells via the gastrointestinal microbiota (Bacteroides acidifaciens, Odoribacter laneus, and Odoribacter splanchnicus)-AMPK-mTOR axis.Conclusions Our study uncovers the role of DMC in improving the tumor microenvironment of HCC, which not only enriches the relationship between the mPGES-1/prostaglandin E2 pathway and the antitumor function of NK and T cells, but also provide an important strategic reference for multitarget or combined immunotherapy of HCC.Cite No