DUSP2 methylation is a candidate biomarker of outcome in head and neck cancer.

BACKGROUND: Biomarkers predictive of response to chemoradiotherapy (CRT) regimens for locally advanced head and neck squamous cell carcinoma (LA-HNSCC) are urgently required to identify patients in whom this approach is likely to be effective. TP53 mutations and epidermal growth factor (EGFR) overexpression are common markers of disease. Dual-specificity-phosphatase-2 (DUSP2) has an essential role in cell proliferation, cancer and immune responses. METHODS: Aberrant DUSP2 methylation was investigated by pyrosequencing in 5 HNSCC cell lines, 112 LA-HNSCC tumours. EGFR was investigated by immunohistochemistry and TP53 was analysed by sequencing. RESULTS: We demonstrate methylation-dependent transcriptional silencing of DUSP2 in HNSCC cell lines. In LA-HNSCC patients, aberrant methylation in the DUSP2 CpG island was present in 51/112 cases (45.5%). LA-HNSCC cases with wild-type TP53, overexpression of EGFR and unmethylated DUSP2 had the worst overall survival (P≤0.001). CONCLUSIONS: DUSP2 methylation, when combined with EGFR and TP53, is a candidate biomarker of clinical outcome in LA-HNSCC treated with CRT.

Novel multi-target directed ligand-based strategies for reducing neuroinflammation in Alzheimer's disease.

Alzheimer's disease (AD) is one of the most common causes of dementia. AD pathogenesis has been hypothesized to involve cholinergic deficits, amyloid-beta protein (Aß) deposition, tau protein hyperphosphorylation, and chronic neuroinflammation. Many single-target drugs have gone through the various stages of pre-clinical and clinical development in an effort to cure AD; however, the current clinically approved drugs have only limited effects on the disease progression. With the accumulation of unsuccessful clinical trials using single-target drugs, multi-target directed ligand (MTDL) drug development is becoming more common. MTDLs incorporate two or more pharmacophores into a single drug molecule. This approach can alleviate side effects and lead to a better pharmacokinetic profile of the MTDL compared to two or more separate drugs representing respective single pharmacophores. This review discusses cathepsin B (CatB), dual specificity phosphatase 2 (DUSP2), and monoglycerol lipase (MAGL) as targets for MTDLs aimed at slowing down the neuroinflammatory component of neurodegenerative diseases. CatB, DUSP2 and MAGL inhibitors show promising preclinical anti-inflammatory effects in vivo and in vitro. Incorporating pharmacophores that inhibit these targets into MTDLs represents a promising avenue towards effective suppression of neuroinflammation associated with AD.

Differential expression of DUSP2 in left- and right-sided colon cancer is associated with poor prognosis in colorectal cancer.

Dual-specificity phosphatase-2 (DUSP2), a negative regulator of extracellular-regulated kinase activity, has been identified as an important kinase with emerging roles in cancer. However, the clinical significance of DUSP2 in colorectal cancer (CRC) remains to be fully elucidated. In the present study, the expression of DUSP2 was investigated using immunohistochemistry in 96 patients with CRC. Cell viability was estimated using a cell counting kit-8 assay, and cell apoptosis by flow cytometry. The relationship between DUSP2 expression and patient characteristics, including overall survival, were studied retrospectively in these patients. It was found that DUSP2 was differentially expressed between left-sided colon carcinoma (LSCC) and right-sided colon carcinoma (RSCC). It was also found that decreased expression of DUSP2 was correlated with significantly shorter overall survival (P=0.001) and short distant-metastasis-free survival (P=0.002). In univariate comparisons, the decreased expression of DUSP2 was found to be an independent risk factor for poor survival rate (HR 3.55, CI 1.092-9.896; P=0.002). It was also found that the enforced overexpression of DUSP2 sensitized CRC cells to cetuximab. In conclusion, the findings demonstrated that DUSP2 was differentially expressed between RSCC and LSCC, and that the overexpression of DUSP2 increased the inhibitory effect of cetuximab in CRC, suggesting that DUSP2 may be a novel biomarker and therapeutic target in CRC therapy.

The effect of DUSP2 on proliferation and apoptosis of gastric cancer cells and its mechanism / 天津医药

@#Objective To investigate the effect of dual-specificity phosphatase-2 (DUSP2) on the cell proliferation and apoptosis in the gastric cancer and its mechanisms. Methods Firstly, the effects of different expressions of DUSP2 on the overall survival of 876 gastric cancer patients were analyzed by online analysis tool KM plotter, and the expressions of DUSP2 in various gastric cancer cell lines (MKN-45, SGC-7901, HGC-27 and N-87) were verified. Secondly, DUSP2 overexpressed lentiviral vector was constructed, and MKN-45 was transfected by packaged virus. DUSP2-overexpression gastric cancer cell line was gained by drug screening. Meanwhile, gastric cancer cells infected with empty vector virus were used as control. Then the effect of DUSP2 upregulation on the proliferation ability of gastric cancer cells was evaluated by MTS cell proliferation assay, and the apoptosis was determined by Annexin V-FITC / PI double staining. The protein expressions of DUSP2, ERK, p-ERK (Thr202/Tyr204), P38 and p-P38 were tested by the Western blot analysis. Results Gastric cancer patients with high DUSP2 expression showed a significant survival advantage compared with those with low DUSP2 expression, and DUSP2 levels were decreased in several gastric cancer cell lines. The Western blot analysis revealed that the expression of DUSP2 markedly increased in overexpressed DUSP2 group (experimental group) compared with that of control group. The MTS experiment showed that the cell viability was significantly decreased in experimental group than that of the control group. Correspondingly, the cell apoptosis test showed that the cell apoptosis rate was obviously higher in the experimental group than that of the control group. The results of Western blot assay indicated that p-ERK (Thr202/Tyr204) and p-38 were significantly down-regulated in the experimental group compared with those of control group. Conclusion The over-expression of DUSP2 can efficiently inhibit cell proliferation and promote its apoptosis in gastric cancer cells, and the mechanism is related to DUSP2 inhibiting the phosphorylation levels of ERK and P38.

Hypoxia-inhibited DUSP2 expression promotes IL-6/STAT3 signaling in endometriosis.

PROBLEM: How does hypoxia-mediated downregulation of dual-specificity phosphatase-2 (DUSP2) promote the development of endometriotic lesions? METHOD OF STUDY: The levels of IL-6 and DUSP2 were assessed in eutopic stromal cells with DUSP2 knockdown or hypoxia treatment. Bromodeoxyuridine (BrdU) incorporation was applied for evaluating cell proliferation. The protein levels of DUSP2, cleaved caspase-3, phosphorylated STAT3, and STAT3 were analyzed using immunoblot. RESULTS: The genomewide analysis of cells with DUSP2 overexpression indicated IL-6 regulates multiple pathways related to inflammation, proliferation, and apoptosis. DUSP2 overexpression significantly suppressed IL-6 expression, while DUSP2 knockdown promoted IL-6 expression. The hypoxia-treated eutopic stromal cells expressed higher levels of IL-6, recapitulating the elevated levels of IL-6 in ectopic stromal cells. The treatment with IL-6 elicited the phosphorylation of STAT3, mimicking the elevated levels of phosphorylated STAT3 in the ectopic stromal cells. The IL-6-treated eutopic stromal cells showed more BrdU incorporation and less cleaved caspase-3, which can be reversed by STAT3 inhibitor. CONCLUSION: Hypoxia-induced IL-6 production in endometriotic lesions is mediated via downregulation of DUSP2, which causes aberrant activation of STAT3 signaling pathway and helps the endometriotic cells survive under the ectopic environment.

Inhibition of dual specificity phosphatase-2 by hypoxia promotes interleukin-8-mediated angiogenesis in endometriosis.

STUDY QUESTION: How does hypoxia-mediated down-regulation of dual specificity phosphatase-2 (DUSP2) promote endometriotic lesion development? SUMMARY ANSWER: Inhibition of DUSP2 by hypoxia enhances endometriotic lesion growth via promoting interleukin-8 (IL-8)-dependent angiogenesis. WHAT IS KNOWN ALREADY: Angiogenesis is a prerequisite for the development of endometriosis. DUSP2 is down-regulated in endometriotic stromal cells in a hypoxia inducible factor-1α-dependent manner. Down-regulation of DUSP2 contributes to the pathological process of endometriosis. STUDY DESIGN, SIZE, DURATION: A laboratory study recruiting 20 patients of reproductive age with endometriosis and normal menstrual cycles, and an autoimplant-induced mouse model of endometriosis using 13 mice in a 28-day treatment. PARTICIPANTS/MATERIALS, SETTING, METHODS: IL-8 mRNA levels were assayed in endometrial stromal cells maintained in normoxic or hypoxic (1% O2) conditions, with or without DUSP2 knockdown. Promoter activity and chromatin immunoprecipitation (ChIP) assays were conducted to characterize the regulation of IL-8 by DUSP2. Conditioned media from cells maintained in normoxic or hypoxic conditions, and cells with/without DUSP2 knockdown were collected to investigate the angiogenic capacity using an in vitro tube formation assay. Reparixin, an IL-8 receptor blocker, was administered to investigate the role of IL-8 in hypoxia-mediated angiogenesis and the development of endometriotic-like lesions in an autotransplanted mouse model. MAIN RESULTS AND THE ROLE OF CHANCE: IL-8 mRNA was increased by both hypoxia and DUSP2 knockdown in endometrial stromal cells in an extracellular signal-regulated protein kinase-dependent manner (P < 0.05 versus control). Promoter activity and ChIP assays demonstrated that expression of IL-8 was regulated by CCAAT/enhancer binding protein α (P < 0.05 versus control). Furthermore, conditioned media collected from hypoxia-exposed or DUSP2 knockdown endometrial stromal cells promoted tube formation, which was abolished by co-treatment with reparixin (P < 0.05 versus control). Results from the autotransplanted mouse model demonstrated that number of blood vessels and size of endometriotic-like lesions were markedly reduced in recipient mice treated with reparixin (P < 0.05 versus control). LIMITATIONS, REASONS FOR CAUTION: This study was conducted in primary human cell cultures and a mouse model, therefore may not fully reflect the situation in vivo. WIDER IMPLICATIONS OF THE FINDINGS: This is the first study to highlight the potential application of an IL-8 receptor blocker as a therapeutic target to treat endometriosis. This study demonstrates IL-8 as a key angiogenic factor regulated by hypoxia/DUSP2, which suggests an alternative mechanism through which hypoxia may promote angiogenesis. STUDY FUNDING/COMPETING INTERESTS: This study was funded by the National Science Council of Taiwan (NSC101-2314-B-006-043-MY2). The author declares that there is no conflict of interest.