Retraction Notice to: lncRNA ILF3-AS1 promotes proliferation and metastasis of colorectal cancer cells by recruiting histone methylase EZH2.

[This retracts the article DOI: 10.1016/j.omtn.2021.04.007.].

lncRNA ILF3-AS1 promotes proliferation and metastasis of colorectal cancer cells by recruiting histone methylase EZH2.

The role of long non-coding RNA (lncRNA) has been displayed in colorectal cancer (CRC). Here, we aimed to discuss the role of lncRNA interleukin enhancer-binding factor 3-antisense RNA 1 (ILF3-AS1)/enhancer of zeste homolog 2 (EZH2)/cyclin-dependent kinase inhibitor 2 (CDKN2A)/histone 3 (H3) lysine 27 trimethylation (H3K27me3) in cell proliferation and metastasis of CRC. ILF3-AS1, EZH2, and CDKN2A levels in CRC tissues and cells were detected. The relationship between ILF3-AS1/EZH2 expression and the clinicopathological features of CRC was analyzed. High/low expression of ILF3-AS1/EZH2 plasmids were composed to explore the function of ILF3-AS1/EZH2 in invasion, migration, proliferation, colony formation, and apoptosis of CRC cells. The growth status of nude mice was observed to verify the in vitro results from in vivo experiment. ILF3-AS1 and EZH2 increased, whereas CDKN2A reduced in CRC tissues and cells. ILF3-AS1 and EZH2 expression was linked to Dukes stage, distant metastasis, vascular invasion, and lymph node metastasis of CRC patients. Depleted ILF3-AS1 or reduced EZH2 suppressed proliferation, migration, colony-formation, and invasion ability, as well as facilitated apoptosis of CRC cells and attenuated the tumor growth in CRC mice. ILF3-AS1 accelerates the proliferation and metastasis of CRC cells by recruiting histone methylase EZH2 to induce trimethylation of H3K27 and downregulate CDKN2A.

Radiation therapy enhanced therapeutic efficacy of anti-PD1 against gastric cancer.

Radiation therapy is an important method in tumor treatment with distinct responses. This study aimed to investigate the immune effects of radiation therapy on the syngeneic gastric tumor model. Mouse forestomach carcinoma (MFC) cells were irradiated with different X-ray doses. Cell proliferation was determined by clonogenic assay. Gene and protein expression were determined by real-time quantitative PCR and western blot, respectively. The tumor model was established by subcutaneously injecting tumor cells in 615-(H-2 K) mice. Levels of immune-related factors in tumor tissues were determined by immunohistochemistry and flow cytometry. 5 Gy × 3 (three subfractions with 4 h interval) treatment significantly inhibited cell proliferation. Protein expression of stimulator of interferon genes (Sting) and gene expression of IFNB1, TNFα as well as CXCL-9 significantly increased in MFC cells after irradiation. In the MFC mouse model, no obvious tumor regression was observed after irradiation treatment. Further studies showed Sting protein expression, infiltration of dendritic cells and T cells, and significantly increased PD-1/PD-L1 expression in tumor tissues. Moreover, the irradiation treatment activated T cells and enhanced the therapeutic effects of anti-PD1 antibody against MFC tumor. Our data demonstrated that although the MFC tumor was not sensitive to radiation therapy, the tumor microenvironment could be primed after irradiation. Radiation therapy combined with immunotherapy can greatly improve anti-tumor activities in radiation therapy-insensitive tumor models.

The Long Non-coding RNA HOTTIP Is Highly Expressed in Colorectal Cancer and Enhances Cell Proliferation and Invasion.

Long non-coding RNAs (lncRNAs) are associated with a spectrum of biological processes such as gene regulation on transcriptional and post-transcriptional levels. The HOXA transcript at the distal tip (HOTTIP) lncRNA plays an important role in carcinogenesis; however, the underlying role of HOTTIP in colorectal carcinoma (CRC) remains unknown. The aim of the present study was to evaluate the expression and function of HOTTIP in CRC. In the present study, we analyzed HOTTIP expression levels of CRC patients in tumor and adjacent normal tissue by real-time quantitative PCR. Knockdown of HOTTIP by RNA interference was performed to explore its roles in cell proliferation, migration, and invasion. Our results found that HOTTIP was upregulated in human primary CRC tissues. Knockdown of HOTTIP inhibited CRC cell proliferation, migration, and invasion. Above all, knockdown of HOTTIP could represent a rational therapeutic strategy for CRC.

Development of an LC-MS/MS method for quantification of kadsurenone in rat plasma and its application to a pharmacokinetic study.

A sensitive and rapid LC-MS/MS method was developed and validated for the determination of kadsurenone in rat plasma using lysionotin as the internal standard (IS). The analytes were extracted from rat plasma with acetonitrile and separated on a SB-C18 column (50 × 2.1 mm, i.d.; 1.8 µm) at 30 °C. Elution was achieved with a mobile phase consisting of methanol-water-formic acid (65:35:0.1, v/v/v) at a flow rate of 0.30 mL/min. Detection and quantification for analytes were performed by mass spectrometry in the multiple reaction monitoring mode with positive electrospray ionization m/z at 357.1 → 178.1 for kadsurenone, and m/z 345.1 → 315.1 for IS. Calibration curves were linear over a concentration range of 4.88-1464 ng/mL with a lower limit of quantification of 4.88 ng/mL. The intra- and inter-day accuracies and precisions were <8.9%. The LC-MS/MS assay was successfully applied for oral pharmacokinetic evaluation of kadsurenone using the rat as an animal model.