MicroRNA-298 determines the radio-resistance of colorectal cancer cells by directly targeting human dual-specificity tyrosine(Y)-regulated kinase 1A

BACKGROUND Radiotherapy stands as a promising therapeutic modality for colorectal cancer(CRC);yet,the formidable challenge posed by radio-resistance significantly undermines its efficacy in achieving CRC remission.AIM To elucidate the role played by microRNA-298(miR-298)in CRC radio-resistance.METHODS To establish a radio-resistant CRC cell line,HT-29 cells underwent exposure to 5 gray ionizing radiation that was followed by a 7-d recovery period.The quantification of miR-298 levels within CRC cells was conducted through quantitative RT-PCR,and protein expression determination was realized through Western blotting.Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and proliferation by clonogenic assay.Radio-induced apoptosis was discerned through flow cytometry analysis.RESULTS We observed a marked upregulation of miR-298 in radio-resistant CRC cells.MiR-298 emerged as a key determinant of cell survival following radiation exposure,as its overexpression led to a notable reduction in radiation-induced apoptosis.Intriguingly,miR-298 expression exhibited a strong correlation with CRC cell viability.Further investigation unveiled human dual-specificity tyrosine(Y)-regulated kinase 1A(DYRK1A)as miR-298’s direct target.CONCLUSION Taken together,our findings underline the role played by miR-298 in bolstering radio-resistance in CRC cells by means of DYRK1A downregulation,thereby positioning miR-298 as a promising candidate for mitigating radioresistance in CRC.

Dual-specificity phosphatase 6(DUSP6): a review of its molecular characteristics and clinical relevance in cancer

Mitogen-activated protein kinases(MAPKs) are the main regulators of cellular proliferation, growth, and survival in physiological or pathological conditions. Aberrant MAPK signaling plays a pivotal role in carcinogenesis, which leads to development and progression of human cancer. Dual-specificity phosphatase 6(DUSP6), a member of the MAPK phosphatase family, interacts with specifically targeted extracellular signal-regulated kinase 1/2 via negative feedback regulation in the MAPK pathway of mammalian cells. This phosphatase functions in a dual manner, pro-oncogenic or tumor-suppressive, depending on the type of cancer. To date, the tumor-suppressive role of DUSP6 has been demonstrated in pancreatic cancer, non-small cell lung cancer, esophageal squamous cell and nasopharyngeal carcinoma, and ovarian cancer. Its pro-oncogenic role has been observed in human glioblastoma, thyroid carcinoma, breast cancer, and acute myeloid carcinoma. Both roles of DUSP6 have been documented in malignant melanoma depending on the histological subtype of the cancer. Loss-or gain-of-function effects of DUSP6 in these cancers highlights the significance of this phosphatase in carcinogenesis. Development of methods that use the DUSP6 gene as a therapeutic target for cancer treatment or as a prognostic factor for diagnosis and evaluation of cancer treatment outcome has great potential. This review focuses on molecular characteristics of the DUSP6 gene and its role in cancers in the purview of development, progression, and cancer treatment outcome.

Minibrain-related kinase/dual-specificity tyrosine-regulated kinase 1B implication in stem/cancer stem cells biology

Dual-specificity tyrosine phosphorylation-regulated kinase 1B(DYRK1B),also known as minibrain-related kinase(MIRK)is one of the best functionally studied members of the DYRK kinase family.DYRKs comprise a family of protein kinases that are emerging modulators of signal transduction pathways,cell proliferation and differentiation,survival,and cell motility.DYRKs were found to participate in several signaling pathways critical for development and cell homeostasis.In this review,we focus on the DYRK1B protein kinase from a functional point of view concerning the signaling pathways through which DYRK1B exerts its cell type-dependent function in a positive or negative manner,in development and human diseases.In particular,we focus on the physiological role of DYRK1B in behavior of stem cells in myogenesis,adipogenesis,spermatogenesis and neurogenesis,as well as in its pathological implication in cancer and metabolic syndrome.Thus,understanding of the molecular mechanisms that regulate signaling pathways is of high importance.Recent studies have identified a close regulatory connection between DYRK1B and the hedgehog(HH)signaling pathway.Here,we aim to bring together what is known about the functional integration and cross-talk between DYRK1B and several signaling pathways,such as HH,RAS and PI3K/mTOR/AKT,as well as how this might affect cellular and molecular processes in development,physiology,and pathology.Thus,this review summarizes the major known functions of DYRK1B kinase,as well as the mechanisms by which DYRK1B exerts its functions in development and human diseases focusing on the homeostasis of stem and cancer stem cells.

Isolation and Characterization of GmSTY1,a Novel Gene Encoding a Dual-Specificity Protein Kinase in Soybean（ Glycme max L.）

Phosphorylation of protein klnases has profound effects on their activity and interaction with other proteins. Tyroslne phosphorylation was reported to be involved in various physiological processes in plants; however, no typical receptor tyrosine kinase has been isolated from plants thus far. Dual-specificity kinases are potentially responsible for the phosphorylation of both tyrosine and serine/threonine of target proteins. A cDNA clone encoding a putative dual-specificity protein kinase was isolated by screening the cDNA GAL4 activation domain （AD） fusion library of soybean （Glycine max L.）, and its entire length was obtained using 5＇-rapid ampUflcatlon of cDNA ends. The predicted polypeptide of 330 amino acid residues, designated as GmSTY1, contains all 11 conserved subdomains, which share common characteristics with both the serine/ threonine and tyroslne protein klnases reported thus far. In addition, three potential N-linked glycosylation sites （NXS/T）, as well as phosphorylation motifs （SXXXS/T）, were observed, suggesting that GmSTY1 may be post-translationally modified. Furthermore, a potential N-myristoylation motif （MGARCSK） was found, suggesting that the GmSTY1 protein could associate with membranes in vivo. Southern blotting analysis revealed a single-copy of GmSTY1 in the genome. Northern blotting analysis showed that this gene was upregulated by drought and salt treatment in a time-dependent manner; however, exogenous abscisic acid （ABA） could not significantly affect the mRNA accumulation of GmSTY1. Interestingly, the transcript of this gene was remarkably downregulated by cold treatment during the early stages of the response, but upregulated later. These results Indicate that the protein kinase was possibly regulated by abiotic stresses in an ABA-independent pathway.

Dual-specificity Phosphatase 1 Deficiency Induces Endometrioid Adenocarcinoma Progression via Activation of Mitogen-activated Protein Kinase/Extracellular Signal-regulated Kinase Pathway

Background： Previously, we reported that dual-specificity adenocarcinoma （EEA）. However, the role of DUSP1 medroxyprogesterone （MPA） are still unclear. phosphatase I （DUSPI） was differentially expressed in endometrioid in EEA progression and the relationship between DUSPI and Methods： The expression of DUSPI in EEA specimens was detected by immunohistochemical analysis. The effect of DUSPI on cell proliferation was analyzed by Cell Counting Kit 8 and colony formation assay, and cell migration was analyzed by transwell assay. MPA-induced DUSPI expression in EEA cells was measured by Western blot. Results： DUSPI expression was deficient in advanced International Federation of Gynecology and Obstetrics stage, high-grade and myometrial invasive EEA. In EEA cell lines （HeclA, Hecl B, RL952, and Ishikawa）, the DUSP1 expression was substantially higher in lshikawa cells than in other cell lines （P 〈 0.05）. Knockdown ofDUSP I promoted lshikawa cells proliferation, migration, and activation of mitogen-activated protein kinases/extracellular signal-regulated kinase （MAPK/Erk） pathway. MPA-induced DUSP1 expression and inhibited MAPK/Erk pathway in Ishikawa cells. Conclusions： Our data suggest that DUSP1 deficiency promotes EEA progression via MAPK/Erk pathway, which may be reversed by MPA, suggesting that DUSP I may serve as a potential therapeutic target for the treatment of EEA.

KAT7/HMGN1 signaling epigenetically induces tyrosine phosphorylation-regulated kinase 1A expression to ameliorate insulin resistance in Alzheimer’s disease

BACKGROUND Epidemiological studies have revealed a correlation between Alzheimer’s disease(AD)and type 2 diabetes mellitus(T2D).Insulin resistance in the brain is a common feature in patients with T2D and AD.KAT7 is a histone acetyltransferase that participates in the modulation of various genes.AIM To determine the effects of KAT7 on insulin patients with AD.METHODS APPswe/PS1-dE9 double-transgenic and db/db mice were used to mimic AD and diabetes,respectively.An in vitro model of AD was established by Aβstimulation.Insulin resistance was induced by chronic stimulation with high insulin levels.The expression of microtubule-associated protein 2(MAP2)was assessed using immunofluorescence.The protein levels of MAP2,Aβ,dual-specificity tyrosine phosphorylation-regulated kinase-1A(DYRK1A),IRS-1,p-AKT,total AKT,p-GSK3β,total GSK3β,DYRK1A,and KAT7 were measured via western blotting.Accumulation of reactive oxygen species(ROS),malondialdehyde(MDA),and SOD activity was measured to determine cellular oxidative stress.Flow cytometry and CCK-8 assay were performed to evaluate neuronal cell death and proliferation,respectively.Relative RNA levels of KAT7 and DYRK1A were examined using quantitative PCR.A chromatin immunoprecipitation assay was conducted to detect H3K14ac in DYRK1A.RESULTS KAT7 expression was suppressed in the AD mice.Overexpression of KAT7 decreased Aβaccumulation and MAP2 expression in AD brains.KAT7 overexpression decreased ROS and MDA levels,elevated SOD activity in brain tissues and neurons,and simultaneously suppressed neuronal apoptosis.KAT7 upregulated levels of p-AKT and p-GSK3βto alleviate insulin resistance,along with elevated expression of DYRK1A.KAT7 depletion suppressed DYRK1A expression and impaired H3K14ac of DYRK1A.HMGN1 overexpression recovered DYRK1A levels and reversed insulin resistance caused by KAT7 depletion.CONCLUSION We determined that KAT7 overexpression recovered insulin sensitivity in AD by recruiting HMGN1 to enhance DYRK1A acetylation.Our findings suggest that KAT7 is a novel and promising therapeutic target for the resistance in AD.

Fermented Barley Extracts with Lactobacillus plantarum dy-1 Rich in Vanillic Acid Modulate Glucose Consumption in Human HepG2 Cells

Objective To investigate the effect of fermented barley extracts with Lactobacillus plantarum dy-1（LFBE） for modulating glucose consumption in HepG2 cells via miR-212 regulation. Methods Hepatocellular carcinoma（HepG2） cells were treated with palmitate. After 12 h, palmitate-induced HepG2 cells were treated with LFBE and its main components. Changes in glucose consumption, proinflammatory cytokine secretion, and miRNA-212 expression in HepG2 cells was observed. Results Treatment with LFBE rich in vanillic acid（VA） increased glucose consumption and reduced proinflammatory cytokine secretion in HepG2 cells. LFBE and VA normalized the upregulation of miR-212, which led to the upregulation of dual-specificity phosphatase-9（DUSP9）, a direct target of miR-212, at both protein and mR NA levels. Downregulation of miR-212 markedly increased glucose consumption and reduced proinflammatory cytokine secretion by enhancing DUSP9 expression. Conclusion The results showed the benefit of LFBE and miR-212 downregulation in modulating glucose consumption and reducing proinflammatory cytokine secretion by targeting DUSP9. VA in LFBE was a strong regulator of palmitate-induced abnormal glucose consumption in HepG2 cells and can be a primary mediator.

Platelet-Activating Factor Induces Du-al-Specificity Phosphatase 1 and 5 Gene Expression

Platelet-activating factor (PAF) is a potent inflammatory phospholipid mediator that is known to play a role in early-phase responses in asthma and other diseases. Through its high affinity receptor, PAFR, PAF is known to activate multiple signalling pathways contributing to its proinflammatory effects. Of these pathways, the mitogen-activated protein kinase (MAPK) cascade is initiated upon PAF stimulation, leading to the activation of the conventional MAPKs ERK1/2, p38 and JNK. Since dual-specificity phosphatases (DUSP) downregulated MAPK activity, we postulated that PAF could also enhance DUSP expression and thus induced an autoregulatory loop. In this report, we studied the effect of PAF on DUSP mRNA expression in human monocytes. Our results demonstrate that PAF induces DUSP1 and DUSP5 gene expression in a time- and concentration-dependent manner, with maximal effects at PAF 100 nM and at 20 - 30 min of stimulation. In contrast, DUSP2 and DUSP6 gene expression was not enhanced by PAF. Moreover, leukotriene D4, another lipid mediator of inflammation, was unable to modulate DUSP expression. PAF-induced DUSP expression was prevented by the PAFR antagonist WEB2170 and by pretreatment with the transcriptional inhibitor Actinomycin D. Moreover, enhanced DUSP5, but not DUSP1 expression was prevented by pretreatment with the ERK inhibitor PD98059 or the PI3K inhibitor Wortmannin. Taken together, our results indicate that PAF selectively enhances DUSP1 and DUSP5 gene expressions through PAFR activation, and suggest that PAF may have an active role in the resolution of inflammation by its ability to upregulate the two DUSPs and thus provide a negative auto-regulatory signalling mechanism.

GPS 5.0: An Update on the Prediction of Kinase-specific Phosphorylation Sites in Proteins

In eukaryotes,protein phosphorylation is specifically catalyzed by numerous protein kinases(PKs),faithfully orchestrates various biological processes,and reversibly determines cellular dynamics and plasticity.Here we report an updated algorithm of Group-based Prediction System(GPS)5.0 to improve the performance for predicting kinase-specific phosphorylation sites(p-sites).Two novel methods,position weight determination(PWD)and scoring matrix optimization(SMO),were developed.Compared with other existing tools,GPS 5.0 exhibits a highly competitive accuracy.Besides serine/threonine or tyrosine kinases,GPS 5.0 also supports the prediction of dual-specificity kinase-specific p-sites.In the classical module of GPS 5.0,617 individual predictors were constructed for predicting p-sites of 479 human PKs.To extend the application of GPS5.0,a species-specific module was implemented to predict kinase-specific p-sites for 44,795 PKs in161 eukaryotes.The online service and local packages of GPS 5.0 are freely available for academic research at http://gps.biocuckoo.cn.

DUSP1 Blocks autophagy-dependent ferroptosis in pancreatic cancer

Ferroptosis is a oxidative damage-dependent form of regulated cell death that has become an emerging target for disease prevention and treatment.Here,we show that dual-specificity phosphatase 1(DUSP1),a phosphatase playing multiple roles in stress-signaling pathways,is a new repressor of ferroptosis in human pancreatic cancer cells.Several classical ferroptosis activators(eg,erastin and RSL3)induce the expression of DUSP1,but not other members of DUSP,which depends on extracellular signal-regulated protein kinases 1 and 2(ERK1/2).Moreover,shRNA-mediated DUSP1 knockdown increases the anticancer activity of ferroptosis activators in pancreatic cancer cells through activating lipid peroxidation in vitro and in vivo.Importantly,DUSP1-mediated autophagy is responsible for lipid peroxidation-mediated ferroptotic cell death.Thus,the DUSP1-related ferroptotic pathway may represent a potential target for therapeutic intervention in pancreatic cancer.