Effects of miR-939 and miR-376A on ulcerative colitis using a decoy strategy to inhibit NF-κB and NFAT expression.

The aim of this study was to explore the effects of miR-939 and miR-376A on the pathogenesis of ulcerative colitis (UC) by using a decoy strategy to regulate the expression of nuclear transcription factor kappa B (NF-κB) and nuclear factor of activated T cells (NFAT). Such strategies represent a potential novel treatment for UC. Quantitative polymerase chain reaction (qPCR) analysis was used to detect the differences between the expression of miR-939, miR-376a, NF-κB, NFAT in the tissue samples from the resting and active stages of UC and healthy controls, and analyzed the correlation. The electrophoretic mobility shift assay was used to validate the ability of miRNAs to bind to NF-κB and NFAT. The expression of components of the intestinal barrier in UC and changes in apoptosis-related factors were examined by western blotting, qPCR, and immunofluorescence. After a dextran sulfate sodium (DSS)-induced mouse model of UC was established, the morphological changes in the colonic tissues of mice, the changes in serum inflammatory factors, and the changes in urine protein or urine leukocytes, liver enzymes, and prothrombin time were measured to examine intestinal permeability. The expression of miR-939 and miR-376a in human UC tissue was significantly lower than that in the normal control tissue, and was negatively correlated with the expression of NF-κB and NFAT. miR-939 and miR-376a decoy strategies resulted in a beneficial increase in the expression of claudins, occludins, and ZO-1 protein and inhibited apoptosis in intestinal epithelial cells. The disease activity index of the UC model group was significantly higher than that of the normal control group. The expression of inflammatory factors in the decoy group was higher than that in the UC model group. Therefore, from the experimental results, it can be concluded that using miR-939 and miR-376a to trap NF-κB and NFAT inhibits the activation of transcription factors NF-κB and NFAT, which in turn inhibits the expression of inflammatory factors and results in partial recovery of the intestinal barrier in UC. The decoy strategy inhibited apoptosis in the target cells and had a therapeutic effect in the mice model of UC. This study provides new ideas for the development of future clinical therapies for UC.

PRRX1 promotes colorectal cancer stemness and chemoresistance via the JAK2/STAT3 axis by targeting IL-6.

Background: Stemness acquirement is one of the hallmarks of cancer and the major reason for the chemoresistance and poor prognosis of colorectal cancer (CRC). Previous research has revealed the stimulatory role of paired related homeobox 1 (PRRX1) on CRC metastasis. However, the role of PRRX1 in stemness acquirement and chemoresistance of CRC is still not clear. Methods: A retrospective cohort study was performed to investigate the relationship between PRRX1 expression and multiple clinicopathological characteristics of CRC patients. The functional effects of PRRX1 on stemness and chemoresistance of CRC cells were validated by in vitro and in vivo assays. Gene set enrichment analysis (GSEA) and JASPAR software were performed to predict the underlying mechanisms. Enzyme-linked immunosorbent assay (ELISA), Western blot, immunofluorescence, and dual-luciferase reporter assays were used to confirm the PRRX1-mediated signaling and its downstream factors. Results: The expression of PRRX1 was up-regulated in CRC tissues and cell lines compared to normal epithelial tissues and cell lines. High expression of PRRX1 was tightly associated with the metastasis, chemoresistance, and poor prognosis of CRC patients. Additionally, PRRX1 significantly promoted the proliferation, viability, stemness, and chemoresistance of CRC cells, as well as the activation of the interleukin-6 (IL-6)/JAK2/STAT3 axis. Inhibiting the expression of IL-6 dramatically eliminated the effects of PRRX1 on CRC cell stemness and chemoresistance. Conclusions: PRRX1 plays a vital role in the stemness and chemoresistance of CRC cells via JAK2/STAT3 signaling by targeting IL-6. Further, PRRX1 may be a valid biomarker for predicting the effect of chemotherapy and prognosis of CRC patients.

A Preliminary Study of miR-144 Inhibiting the Stemness of Colon Cancer Stem Cells by Targeting Krüppel-Like Factor 4.

Colon cancer is a prevalent clinical malignant tumor of the digestive system. The current study aims to explore the miR-144 expression in colorectal cancer (CRC) cell lines and CRC stem cells (CSCs) and to explore its effect on the stemness of CSCs and the targeted regulation of Krüppel-like factor 4 (KLF4). Use qRT-PCR to detect the expression level of miR-144 in CRC cells SW480, HCT116, and H129 and the healthy colon cell NCM460. The CSCs that were used were cultured in HCT116 cells. Use western blot to explore the expressions of Nanog, SOX2, and OCT4 stemness marker protein. After it was transfected with miR-144 mimics or KLF4 plasmid, use MTT to explore the cell viability of CSCs, use flow cytometry to evaluate apoptosis, and use transwell assay to evaluate the ability of invasive of CSCs. The targeting effect of miR-144 on the KLF4 gene was verified using TargetScan prediction and the double-luciferase reporter gene test. Use qRT-PCR to evaluate the role of miR-144 mimics on KLF4 mRNA expression in CSCs. The qRT-PCR results exhibited that the miR-144 expression in CRC cells was higher than that in the healthy colon cell line. The expressions of OCT4, Nanog, and SOX2 stem cell markers were up-regulated in CSCs, and the expression of miR144 increased in CSCs. The cell viability, apoptosis, and invasion of CSCs increased after miR-144 was transfected. The TargetScan prediction and double-luciferase reporter gene assay confirmed that miR-144 was targeted by KLF4, and the expression of KLF4 mRNA in the miR-144 mimics group reduced. Moreover, the overexpression of KLF4 could partially reverse the role of miR-144 mimics on CSCs. In summary, miR-144 was highly expressed in CRC cell lines and CSCs, and the overexpression of miR-144 in CSCs significantly promoted the proliferation of CSCs, inhibited its apoptosis, and promoted its invasion ability. In addition, its preliminary mechanism, possibly through negative regulation KLF4, promotes the stemness of CSCs, and miR-144 is likely to be a potential target for eliminating CSC from CRC treatment.

Overexpression of MAGT1 is associated with aggressiveness and poor prognosis of colorectal cancer.

Tumor metastasis and anticancer drug resistance are the major causes of mortality in patients with colorectal cancer (CRC). Due to the limitations of conventional biomarkers, it is urgent to identify novel and valid biomarkers to predict the progression and prognosis of CRC. Reverse transcription-quantitative polymerase chain reaction and western blotting were used to detect MAGT1 expression in CRC clinical samples or cell lines. Bioinformatics analysis was used to investigate the association between MAGT1 alteration and clinicopathological features of patients with CRC. The present study revealed that the transcription levels of magnesium transporter 1 (MAGT1) were significantly increased in CRC tissues compared with matched adjacent normal tissues. Overexpression of MAGT1 was associated with advanced tumor stage, N and M classification. In addition, for patients who underwent chemotherapy, patients in the MAGT1-low expression group exhibited a longer overall survival (OS) time than patients in the high-expression group. Patients with CRC treated with chemotherapy had a longer OS time than those treated without chemotherapy in the MAGT1-low expression group but not in the MAGT1-high expression group. Furthermore, MAGT1 was a valid but not an independent prognostic factor for CRC. Therefore, the present study highlighted that MAGT1 may serve as a valid biomarker for predicting the development, progression and poor prognosis of CRC.

Changes of zeatin riboside content in rice plants due to infestation by Nilaparvata lugens (Homoptera: Delphacidae).

The effect of Nilaparvata lugens (Stål) (Homoptera: Delphacidae), infestation on the content of zeatin ribosides (ZR) in rice plants was investigated with enzyme-linked immunosorbent assay. Hydroponics experiments were conducted on 'Zhendao 2' rice, in which plants were subjected to N. lugens infestation at three nonhopperburn-causing densities (15, 30, and 60 nymphs per hill) for 2, 4, 6, and 8 d and at one hopperburn-causing density (240 nymphs per hill) for 2, 4, and 6 d, respectively. When rice plants were infested at the nonhopperburn-causing densities, ZR content in leaves varied significantly with the infestation density. Compared with the control plants, ZR content in rice leaves decreased significantly after infestation by 60 nymphs per hill for 2 d, but it tended to increase due to prolonged infestation at all the nonhopperburn-causing densities. In contrast, ZR content in rice roots significantly reduced after the plants being infested at the density of 15 nymphs for 2 d and at all densities for prolonged duration, except for the plants infested by 60 nymphs for 6 and 8 d, in which the ZR content increased or did not change significantly. However, infestation at the hopperburn-causing density caused significant reduction in ZR content in rice roots, regardless of infestation duration, and in rice leaves from the plants subjected to 2-d infestation. These results are discussed in relation to the possible physiological reaction of rice plants to N. lugens infestation and the resultant severe damage or hopperburn.