The mitogen-activated protein kinases (MAPKs) are key regulators of cell growth and survival in physiological and pathological processes. Aberrant MAPK signaling plays a critical role in the development and progression of human cancer, as well as in determining responses to cancer treatment. The MAPK phosphatases (MKPs), also known as dual-specificity phosphatases (DUSPs), are a family of proteins that function as major negative regulators of MAPK activities in mammalian cells. Studies using mice deficient in specific MKPs including MKP1/DUSP1, PAC-1/DUSP2, MKP2/DUSP4, MKP5/DUSP10 and MKP7/DUSP16 demonstrated that these molecules are important not only for both innate and adaptive immune responses, but also for metabolic homeostasis. In addition, the consequences of the gain or loss of function of the MKPs in normal and malignant tissues have highlighted the importance of these phosphatases in the pathogenesis of cancers. The involvement of the MKPs in resistance to cancer therapy has also gained prominence, making the MKPs a potential target for anti-cancer therapy. This review will summarize the current knowledge of the MKPs in cancer development, progression and treatment outcomes.
Animals ; Dual-Specificity Phosphatases ; Homeostasis ; Humans ; Mice ; Mitogen-Activated Protein Kinase Phosphatases* ; Mitogen-Activated Protein Kinases ; Pathologic Processes ; Phosphoric Monoester Hydrolases

OBJECTIVE: To assess the association of single nucleotide polymorphisms (SNPs) of dual specificity phosphatase 9 (DUSP9) gene rs5945326 locus with gestational diabetes mellitus (GDM). METHODS: Genotypes for the rs5945326 locus were determined for 206 pregnant women with GDM (GDM group) and 189 unaffected pregnant women (control group). Allelic and genotypic frequencies of the GDM and control groups were compared. For individuals with various genotypes, the level of blood glucose, serum lipids, and body mass index (BMI) were also compared. RESULTS: The frequencies of AA, AG and GG genotypes for the GDM group were 32.2%, 52.2% and 15.6%, respectively, and 41.2%, 43.9% and 15.0%, for the control group, respectively. No significant difference was detected in the distribution of above genotypes between the two groups (chi-square=3.601, P=0.165). The frequencies of alleles A and G were 58.3% and 41.7% in the GDM group, and 63.1% and 36.9% in the control group, respectively. No significant difference was detected between the two groups too (chi-square=1.894, P=0.188). The high density lipoprotein (HDL) levels of the GG genotype [(2.34×0.61) mmol/L] was significantly higher than that of the AG+AA genotype [(2.06×0.56) mmol/L] (t=2.993, P=0.003). No significant difference was detected in other clinical indexes between the two groups (P> 0.05). CONCLUSION The SNP rs5945326 in DUSP9 gene may be not associated with the risk of GDM. However, there are correlated with HDL levels.
Alleles ; Diabetes, Gestational ; genetics ; Dual-Specificity Phosphatases ; genetics ; Female ; Gene Frequency ; Genotype ; Humans ; Mitogen-Activated Protein Kinase Phosphatases ; genetics ; Polymorphism, Single Nucleotide ; Pregnancy

BACKGROUND: Toll-like receptors (TLRs) are well-known pattern recognition receptors. Among the 13 TLRs, TLR2 is the most known receptor for immune response. It activates mitogen-activated protein kinases (MAPKs), which are counterbalanced by MAPK phosphatases [MKPs or dual-specificity phosphatases (DUSPs)]. However, the regulatory mechanism of DUSPs is still unclear. In this study, the effect of a TLR2 ligand (TLR2L, Pam3CSK4) on DUSP4 expression in Raw264.7 cells was demonstrated. METHODS: A Raw264.7 mouse macrophage cell line was cultured in Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum and 1% antibiotics (100 U/mL penicillin and 100 g/mL streptomycin) at 37degrees C in 5% CO2. TLR2L (Pam3CSK4)-mediated DUSP4 expressions were confirmed with RT-PCR and western blot analysis. In addition, the detection of reactive oxygen species (ROS) was measured with lucigenin assay. RESULTS: Pam3CSK4 induced the expression of DUSP1, 2, 4, 5 and 16. The DUSP4 expression was also increased by TLR4 and 9 agonists (lipopolysaccharide and CpG ODN, respectively). Pam3CSK4 also induced ERK1/2 phosphorylation and ROS production, and the Pam3CSK4-induced DUSP4 expression was decreased by ERK1/2 (U0126) and ROS (DPI) inhibitors. U0126 suppressed the ROS production by Pam3CSK4. CONCLUSION: Pam3CSK4-mediated DUSP4 expression is regulated by ERK1/2 and ROS. This finding suggests the physiological importance of DUSP4 in TLR2-mediated immune response.
Acridines ; Animals ; Anti-Bacterial Agents ; Blotting, Western ; Butadienes ; Cell Line ; Dual-Specificity Phosphatases ; Macrophages ; Mice ; Mitogen-Activated Protein Kinase Phosphatases ; Mitogen-Activated Protein Kinases ; Nitriles ; Penicillins ; Phosphorylation ; Phosphotransferases ; Reactive Oxygen Species ; Receptors, Pattern Recognition ; Toll-Like Receptors

OBJECTIVETo investigate the effects of protein tyrosine phosphatase-SHP2 and dual-specificity MAPK phosphatase-MKP5 on the activation of MAPKs and cell invasion induced by P2Y purinergic receptor in human prostate cancer cell lines with different metastatic potentials.

METHODSThe wide type (-wt) SHP2, mutant type (-cs) SHP2 and wide type (-wt) MKP5 cDNA expression vectors were constructed and stably transfected into 1E8 cells (highly metastatic) and/or 2B4 cells (non-metastatic). The tyrosine phosphorylation of SHP2 was examined by immunoprecipitation. The activation of ERK1/2 and p38 induced by P2Y receptor agonist ATP was analyzed by Western blot with phospho-specific antibodies against the dually phosphorylated, active forms of ERK1/2 and p38. The in-vitro invasive ability through Matrigel was measured by boyden-chamber assay.

RESULTSATP induced significant SHP2 phosphorylation, which was stronger and lasted longer in 1E8 than in 2B4. SHP2-wt enhanced the ERK1/2 activation induced by ATP in 2B4 cells, while SHP2-cs delayed and decreased this effect in 1E8 cells. Both SHP2-wt and SHP2-cs had no obvious influence on p38 activation. ATP stimulated cell invasion of both 1E8 and 2B4, while transfection of SHP2-wt into 2B4 cells further increased the invasive-stimulating ability of ATP (18.7% increase compared with ATP treatment alone). Transfection of SHP2-cs into 1E8 cells, however, antagonized the invasive-stimulating ability of ATP (40.9% decrease compared with ATP treated group). Up-regulation of MKP5-wt inhibited phosphorylation of p38 by ATP and reduced cell invasion stimulated by ATP (22.4% and 28.7% decrease compared with ATP treated group of 1E8 and 2B4, respectively).

CONCLUSIONSBoth SHP2 and MKP5 play some roles in P2Y receptor-mediated activation of MEK/ERK, p38 signaling pathways and prostate cancer invasion. SHP2 positively regulates ERK activation and prostate cancer invasion, whereas MKP5 inhibits the invasion by suppressing p38 activation.

Adenosine Triphosphate ; pharmacology ; Cell Line, Tumor ; DNA, Complementary ; genetics ; Dual-Specificity Phosphatases ; Genetic Vectors ; Humans ; Intracellular Signaling Peptides and Proteins ; genetics ; metabolism ; Male ; Mitogen-Activated Protein Kinase 1 ; metabolism ; Mitogen-Activated Protein Kinase 3 ; metabolism ; Mitogen-Activated Protein Kinase Phosphatases ; Neoplasm Invasiveness ; Phosphorylation ; Prostatic Neoplasms ; metabolism ; pathology ; Protein Tyrosine Phosphatase, Non-Receptor Type 11 ; Protein Tyrosine Phosphatases ; genetics ; metabolism ; Receptors, Purinergic P2 ; physiology ; Signal Transduction ; Transfection ; p38 Mitogen-Activated Protein Kinases ; metabolism

This study aims to decipher the mechanism underlying the effect of Shaofu Zhuyu Decoction on endometriosis(EMT)-associated dysmenorrhea in rats with the syndrome of cold coagulation and blood stasis based on mitogen-and stress-activated protein kinase 1/2(MSK1/2).We employed a random number table to randomly assign SPF female non-pregnant rats into the sham group, and treated the rest rats with autologous transplantation+refrigerator freezing for the modeling of the syndrome of cold coagulation and blood stasis.The modeled rats were then randomly assigned into the control group and high-, medium-and low-dose Shaofu Zhuyu Decoction groups.The rats in the low-, medium-, and high-dose decoction groups were respectively administrated with 9, 4.5, and 2.3 g·kg~(-1) decoction through gavage once a day for 2 consecutive weeks, and those in the control group were administrated with 0.24 mg·kg~(-1) gestrinone through gavage once every 3 days for 2 weeks.After that, the size of ectopic focus in each rat was measured via laparotomy.Enzyme-linked immunosorbent assay(ELISA) was adopted to determine the expression of interleukin(IL)-6, IL-10, prostaglandin E2(PGE2), tumor necrosis factor-α(TNF-α).Western blot was employed to determine the protein levels of MSK1/2 and dual-specificity phosphatase 1(DUSP1) and real-time quantitative polymerase chain reaction(RT-PCR) to determine the mRNA levels of the two genes in rat eutopic endometrial tissue.Compared with the sham group, the model group showed increased levels of IL-6, PGE2, and TNF-α while decrease level of IL-10 in the serum(P<0.01).Compared with the model group, the high-and medium-dose decoction groups and the gestrinone group had declined levels of IL-6, PGE2, and TNF-α while risen level of IL-10 in the serum(P<0.01).The model group had lower protein levels and mRNA levels of MSK1/2 and DUSP1 in the eutopic endometrial tissue than the sham group(P<0.01). The high-and medium-dose decoction groups and the gestrinone group had higher protein and mRNA levels of MSK1/2 and DUSP1 in the eutopic endometrial tissue than the model group(P<0.01).The results indicated that Shaofu Zhuyu Decoction can regulate the abnormal expression of pro-inflammatory cytokines TNF-α, IL-6, and PGE2 and anti-inflammatory cytokines IL-10 and DUSP1 via MSK1/2 to alleviate EMT-associated dysmenorrhea in rats with the syndrome of cold coagulation and blood stasis.
Animals ; Female ; Rats ; Anti-Inflammatory Agents/therapeutic use* ; Cytokines ; Dinoprostone ; Drugs, Chinese Herbal/therapeutic use* ; Dual-Specificity Phosphatases ; Dysmenorrhea/genetics* ; Endometriosis/genetics* ; Gestrinone/therapeutic use* ; Interleukin-10 ; Interleukin-6 ; Mitogen-Activated Protein Kinase 8/therapeutic use* ; Mitogens/therapeutic use* ; RNA, Messenger ; Tumor Necrosis Factor-alpha/metabolism*

OBJECTIVETo explore the molecular mechanisms of G(2)/M checkpoint initiated by diallyl disulfide (DADS) in HL-60 cells.

METHODSCell viability was determined by MTT assay. Cell cycle was assayed by flow cytometry. The expression of phospho-p38, Cdc25B and Cdc2, and p38 mRNA were measured by Western blotting and RT-PCR, respectively.

RESULTSAfter treatment with DADS at 5 - 160 micro mol/L for 0 - 72 h, the growth of HL-60 cells were suppressed in a concentration-dependent manner and the inhibitory effect of DADS (20 micro mol/L) was similar to that of ATRA (10 nmol/L) (P > 0.05). Incubation of HL-60 cells with DADS (20 micro mol/L) for 12 h could activate G(2)/M checkpoint and increase the expression of phospho-p38 MAPK, followed by the expression of phospho-Cdc25B and phospho-Cdc2 (P < 0.05). SB202190, a specific inhibitor of p38 MAPK, markedly blocked the phosphorylation of p38 MAPK, Cdc25B and Cdc2 (P < 0.05).

CONCLUSIONDADS could induce the G(2)/M arrest in HL-60 cells which may be involved in the activation of p38 MAP kinase.

Allyl Compounds ; pharmacology ; Blotting, Western ; CDC2 Protein Kinase ; genetics ; metabolism ; Cell Division ; drug effects ; Cell Proliferation ; drug effects ; Cell Survival ; drug effects ; Disulfides ; pharmacology ; Dose-Response Relationship, Drug ; Enzyme Activation ; drug effects ; Flow Cytometry ; G2 Phase ; drug effects ; Gene Expression ; drug effects ; HL-60 Cells ; Humans ; Phosphorylation ; drug effects ; Reverse Transcriptase Polymerase Chain Reaction ; cdc25 Phosphatases ; genetics ; metabolism ; p38 Mitogen-Activated Protein Kinases ; genetics ; metabolism