NSUN5-FTH1 Axis Inhibits Ferroptosis to Promote the Growth of Gastric Cancer Cells.

Recent studies revealed that NOP2/Sun RNA methyltransferase 5 (NSUN5) - ferritin heavy chain (FTH1) pathway is associated with ferroptosis in stem cells, whereas its roles in gastric cancer are still unclear. Our study aims to investigate the roles of the NSUN5-FTH1 axis in gastric cancer (GC) and its molecular mechanisms. Stable cell lines were constructed on SGC7901 cells by using shRNAs and pcDNA3.1 expression vectors, respectively. CCK-8 kits were used to determine cell viability. Biochemicals assays were used to detect lipid reactive oxygen species (ROS) and intracellular Fe2+ levels. RNA immunoprecipitation assay, qPCR, and Western blotting were used to determine the changes in biomarkers. GC xenograft mouse model was established to confirm the observation in vivo. An elevation of NSUN5 was observed in GC tumor tissues. NSUN5 inhibited ferroptosis including decreasing cell viability and increasing levels of lipid ROS and Fe2+ in GC cells. Besides, a positive correlation was also observed between NSUN5 and FTH1. Interestingly, NSUN5 regulated the levels of FTH1, instead of FTH1 regulating NSUN5 in GC cells. NSUN5-FTH1 axis regulated erastin-induced ferroptosis in SGC7901 cells. Consistently, silencing NSUN5 or FTH1 inhibited the growth of the SGC7901 tumor in vivo. NSUN5-FTH1 axis promoted the growth of GC cells in part by the regulation of ferroptosis.

Homoharringtonine Attenuates Dextran Sulfate Sodium-Induced Colitis by Inhibiting NF-κB Signaling.

Homoharringtonine (HHT) exhibits an anti-inflammatory activity. The potential protective effects and mechanisms of HHT on dextran sulfate sodium- (DSS-) induced colitis were investigated. DSS-induced colitis mice were intraperitoneally injected with HHT. Body weight, colon length, disease activity index (DAI), and histopathological change were examined. The relative contents of interleukin- (IL-) 1ß, tumor necrosis factor- (TNF-) α, IL-6, and the chemokine (C-C motif) ligand 2 (CCL2) in the colon tissues and HHT-treated RAW264.7 cells were detected with the enzyme-linked immunosorbent assay. In the meantime, the levels of p-p65 and p-IκBα were detected by Western blot. The proportion of macrophages (CD11b+F4/80+) in the colon tissues was detected by flow cytometry. HHT alleviated DSS-induced colitis with downregulated TNF-α, IL-1ß, IL-6, and CCL2 expression; reduced activation of nuclear factor-kappa B (NF-κB) signaling; and diminished proportion of recruited macrophages in colon tissues. It was further testified that HHT inhibited lipopolysaccharide-induced macrophage activation with reduced activation of NF-κB signaling. In addition, HHT inhibited the M1 polarization of both human and mouse macrophages, while HHT did not affect the differentiation of human CD4 T cells into Th17, Th1, or Treg cells and did not affect the proliferation and migration of human colon epithelial cells. In summary, HHT attenuates DSS-induced colitis by inhibiting macrophage-associated NF-κB activation and M1 polarization, which could be an option for the treatment of ulcerative colitis.

miR-146b-5p promotes colorectal cancer progression by targeting TRAF6.

Increasing evidence highlights the multiple roles of microRNAs (miRs) in the tumorigenesis of colorectal cancer (CRC); however, the molecular mechanism, particularly the target of miR-146b-5p in CRC has not been fully elucidated. The present study aimed to elucidate the influence of miR-146b-5p via regulating tumor necrosis factor receptor-associated factor 6 (TRAF6) in CRC. The expression levels of miR-146b-5p and TRAF6 in CRC tissue and cells were determined by reverse transcription quantitative PCR and western blotting. Binding between miR-146b-5p and TRAF6 was examined using a dual luciferase reporter gene assay. The impact of miR-146b-5p and TRAF6 on proliferation and migration of CRC cells was determined using Cell Counting Kit-8 and Transwell assays, respectively. An animal model of CRC was established to determine the carcinogenic effect of the miR-146b-5p-TRAF6 axis. The results demonstrated that miR-146b-5p was highly expressed in CRC tissue samples compared with in normal adjacent tissue samples and in CRC cells compared with in the normal NCM460 cell line, whereas TRAF6 was expressed at low levels. Overexpression of miR-146b-5p decreased TRAF6 expression in CRC HT29 and SW620 cells. miR-146b-5p targeted and inhibited TRAF6 expression in CRC cells. Furthermore, transfection with a miR-146b-5p mimic promoted the proliferation, migration and invasion of CRC cells and tumor growth; however, these effects were abolished by TRAF6 overexpression. Transfection with a miR-146b-5p inhibitor suppressed the proliferation of CRC cells. Taken together, the results from the present study demonstrated that miR-146b-5p could enhance the initiation and tumorigenesis of CRC by targeting TRAF6. These results will help elucidate the mechanisms underlying CRC development and will facilitate the development of targeted therapy for CRC.

Laparoscopic Surgery Versus Open Surgery for Colorectal Cancer: Impacts on Natural Killer Cells.

Background: Laparoscopic resection is increasingly used in colorectal cancer (CRC). It has been suggested to carry short-term benefits in safety, recovery, and preservation on immune function for patients with CRC. However, the impact of laparoscopic resection on natural killer (NK) cells is largely unclear. METHODS: A total of 200 patients with CRC across Dukes A/B/C stages were randomly assigned to laparoscopic or open resection. The blood samples were collected before and after the surgery. The total number of NK cells was quantified by flow cytometer. Lytic units 35 toward K562 was used to quantify NK cells activity. The outcomes between the groups across pathological stages were also analyzed. RESULTS: The number and activity of NK cells decreased after the surgery in both groups. The laparoscopic group showed a faster recovery rate of NK cells function than the control group as assessed by cell count and lytic activity. Natural killer cells were impaired in a higher degree in patients at Dukes B/C stages. The recovery of NK cells to baseline level at day 7 postsurgery was observed in the laparoscopic group across all 3 stages. CONCLUSION: Generally, laparoscopically assisted surgery resulted in a better preservation on NK cells function. A better outcome was observed in patients with CRC at Dukes B/C stages.

Glycyrrhizin treatment ameliorates post-traumatic stress disorder-like behaviours and restores circadian oscillation of intracranial serotonin.

Post-traumatic stress disorder (PTSD) has become a major disease that threatens human health. Neurotransmitters and the amygdala are found to be critical in the development and maintenance of PTSD. We aim to investigate the role of glycyrrhizin in treating PTSD. Contextual fear extinction and elevated plus maze test were applied to evaluate the anxiety and fear memory. Microdialysis and high-performance liquid chromatography were used to analyze the expression of amygdala neurotransmitters in PTSD animal models and to verify the effects of glycyrrhizin on major neurotransmitters. The protein levels of tryptophan hydroxylase 2 (TPH2) were examined by western bolt. Glycyrrhizin treatment significantly reduced anxiety and fear memory after 1 and 7 days of PTSD modelling. In addition, glycyrrhizin treatment restored the circadian rhythm changes of serotonin and TPH2. The present study found a significant circadian rhythm change of serotonin in the amygdala in PTSD rats. Besides, glycyrrhizin treatment restored the altered serotonin diurnal fluctuations, which raises important implications for PTSD treatment.

MicroRNA-149 sensitizes colorectal cancer to radiotherapy by downregulating human epididymis protein 4.

Human epididymis protein 4 (HE4) was significantly up-regulated in colorectal cancer (CRC), while the potential relevance to radiation resistance of this phenomenon is still elusive. Relative expressions of target genes were quantified by real-time PCR. The protein level was determined by Western blot. The regulatory effect of miR-149 on WFDC2 (gene encoding HE4 protein) expression was analyzed by luciferase reporter assay. The response to radiation was evaluated by clonogenic assay in vitro and xenograft growth in vivo. WFDC2 was aberrantly up-regulated and miR-149 was down-regulated in CRC. MiR-149 repressed WFDC2 expression via directly targeting its 3'UTR region. The ectopic expression of miR-149 significantly sensitized CRC to radiation both in vitro and in vivo. Likewise, we further demonstrated that WFDC2-deficiency remarkably improved the radiation resistance in CRC. Simultaneously, WFDC2 rescue completely abolished the radiation sensitivity imposed by miR-149. Our data suggested that miR-149 sensitized CRC to radiation via directly inhibiting WFDC2/HE4, which would hold great promise for future therapeutic exploitations.