Estrogen-ERα signaling and DNA hypomethylation co-regulate expression of stem cell protein PIWIL1 in ERα-positive endometrial cancer cells.

BACKGROUND: We previously identified PIWIL1 as an oncogene involved in endometrial carcinogenesis. However, the mechanism of Piwil1 mediated regulation of tumorigenesis remains poorly understood. METHODS: The expression levels of target genes in endometrial cancer cells were detected by quantitative reverse transcription-PCR (RT-qPCR) and western blotting. Up- or down-regulation of ERα or PIWIL1 was achieved by transient transfection with expressing plasmids or short hairpin RNA (shRNA). Dual-luciferase reporter assays and chromatin immunoprecipitation (ChIP) were used to demonstrate the ERα bound to the half estrogen response element (half-ERE) located in PIWIL1 promoter. The expression of PIWIL1 and ERα in endometrial carcinoma tissues were investigated using immunohistochemistry and RT-qPCR. The proliferation ability of cancer cells were evaluated by MTT. Methylation status of the PIWIL1 promoter was detected by bisulfite sequencing PCR (BSP). RESULTS: In the present study, we found that PIWIL1 mediated E2-stimulated cancer cell proliferation. In ERα-positive endometrial cancer cells, we demonstrated that estrogen-ERα signaling significantly up-regulated the expression of PIWIL1, which was mediated by binding of the ERα onto the PIWIL1 promoter. Furthermore, we found that a half-ERE in the PIWIL1 promoter was essential for ERα binding. The PIWIL1 promoter was hypomethylated in ERα-positive endometrial cancer cells. Treatment with 5-aza-deoxycytidine (5-aza-dC) could up-regulate PIWIL1 expression. CONCLUSIONS: These findings uncover a novel molecular mechanism by which estrogen-ERα signaling and DNA hypomethylation co-regulate PIWIL1 expression. These findings provide novel insights into the hormonal regulation of PIWIL1 in endometrial cancer and the PIWIL1's role in estrogen-stimulated endometrial carcinogenesis. Video Abstract. (MP4 41319 kb).

4-HNE induces proinflammatory cytokines of human retinal pigment epithelial cells by promoting extracellular efflux of HSP70.

Oxidative stress and subsequent chronic inflammation result in dysfunction of the retinal pigment epithelium (RPE) and represent therapeutic targets in the context of age-related macular degeneration (AMD). However, molecular mechanisms that linked oxidative stress and inflammation still unclear. As an important byproduct of oxidative stress, 4-hydroxynonenal (4-HNE) induces apoptosis and lysosome dysregulation of RPE cells. In the present study, we evaluated cytokines production of RPE cells induced by 4-HNE by using cytokine array and confirmed that 4-HNE induced IL-6, IL-1ß and TNF-α production in a concentration dependent manner. Specifically, 4-HNE also induced IL-10 and TGF-ß production in low concentration. Molecular analysis revealed that intracellular HSP70 inhibited 4-HNE-induced production of pro-inflammatory cytokines, and 4-HNE exerted proinflammatory effects in RPE cells by enhancing extracellular release of HSP70, as efflux inhibitor Methyl-ß-cyclodextrin (MBC) treatment significantly blocked the release of HSP70 and decreased IL-6 production of RPE cells induced by 4-HNE. Meanwhile, HSP70 inducer arimoclomol increased intracellular HSP70 production, but showed no influence on its extracellular level, also performed anti-inflammatory effects in 4-HNE-stimulated RPE cells. Whereas the anti-inflammatory effects of paeoniflorin, an HSP70 inducer simultaneously promoted its extracellular efflux, was lower than arimoclomol. In addition, we further confirmed that MBC exhibited synergetic effect with both paeoniflorin and arimoclomol to inhibit the production of proinflammatory cytokines induced by 4-HNE. Taken together, these results indicate that HSP70 plays a vital role in regulating inflammation of RPE cells induced by oxidative stress and might be a potential novel target for clinical treatment of AMD.

Mechanism of Cross-modal Information Influencing Taste.

Studies on the integration of cross-modal information with taste perception has been mostly limited to uni-modal level. The cross-modal sensory interaction and the neural network of information processing and its control were not fully explored and the mechanisms remain poorly understood. This mini review investigated the impact of uni-modal and multi-modal information on the taste perception, from the perspective of cognitive status, such as emotion, expectation and attention, and discussed the hypothesis that the cognitive status is the key step for visual sense to exert influence on taste. This work may help researchers better understand the mechanism of cross-modal information processing and further develop neutrally-based artificial intelligent (AI) system.

KLHL14, an ovarian and endometrial-specific gene, is over-expressed in ovarian and endometrial cancer.

Ovarian cancer (OC) and endometrial cancer (EC) are two types of the most frequent gynecological malignancies worldwide. However, the prognosis of OC and EC patients remained gloomy. Therefore, there was still an urgent need to identify new biomarkers for early diagnosis and treatment of OC and EC. TCGA datasets were used to screen the KLHL14 expression levels in 18 different types of human cancers. TCGA datasets were also used to analyze the association between KLHL14 expression levels and OS/PFS in OC and EC. Human Protein Atlas was used to detected the KLHL14 protein levels in OC and EC. Kaplan-Meier plotter was used to evaluate the prognostic values of KLHL14 in Ovarian cancer. MAS 3.0 was used to perform GO and KEGG pathway analysis. STRING was used to perform PPI network. KLHL14 was specially expressed in OC and EC samples. Moreover, KLHL14 was found to be up-regulated in all stage of OC and EC samples. By analyzing Kaplan-Meier plotter and TCGA datasets, we found higher KLHL14 expression level was associated with shorter overall and progression-free survival in both OC and EC patients. Furthermore, GO and KEGG analysis of KLHL14 co-expressing genes indicated it played important roles in OC and EC progression. We for the first time reported KLHL14 was specially over-expressed in ovarian and endometrial cancer, up-regulation of KLHL14 was positively associated with worse outcome. Finally, we found knockdown of KLHL14 suppressed OC cell proliferation. KLHL14 could be a potential biomarker and therapy target for OC and EC.

Tumor Suppressor miR-184 Enhances Chemosensitivity by Directly Inhibiting SLC7A5 in Retinoblastoma.

The expression patterns and functional roles of miRNAs in retinoblastoma (RB) are poorly understood, especially those involved in chemoresistance. Here, we validated the expression pattern of 20 potential RB-suppressive miRNAs and confirmed that miR-184 is the most significantly decreased miRNA in human RB tissues, as well as chemoresistant cell line. Bioinformatic and molecular analyses revealed that SLC7A5 has three binding sites of miR-184 and significantly increased in RB tissues. miR-184 negatively correlated with SLC7A5 expression in RB tissues and mainly target position 2494-2513 of the SLC7A5 3'UTR to inhibit its expression. Furthermore, enforced expression of miR-184 reversed the oncogenic roles of SLC7A5 on proliferation, migration, and invasion of RB cells. In addition, miR-184 also enhances chemosensitivity of RB cells via inducing apoptosis and G2/M cell cycle arrest. Molecular studies revealed that miR-184-decreased phosphorylation status of known DNA damage repair sensors of the ATR/ATM pathways and induced persistent formation of γH2AX foci depend on targeting SLC7A5, leading to persistent DNA damage. Thus, targeting the miR-184/SLC7A5 pathway will provide new opportunities for drug development to reverse chemotherapeutic resistance in RB.

Observation of amyloid precursor protein cleavage and A beta generation in living cells by using multiphoton laser scanning microscopy.

OBJECTIVE: To investigate the proteolytic mechanism of amyloid precursor protein (APP) and to explore amyloid-beta (A beta) generation in living neurons. METHODS: DNA fragments were amplified by PCR or synthesized. The four fragments, CFP, 54bp, YFP and C99 were ligated into pcDNA3.0 vector to construct the recombinant plasmids pcDNA3.0-CFP-54bp-YFP and pcDNA3.0-CFP-54bp-YFP-C99. The SH-SY5Y cells were transiently transfected with pcDNA3.0-CFP-54bp-YFP or pcDNA3.0-CFP-54bp-YFP-C99. The expression of fusion gene was examined under a multiphoton laser scanning microscope. Fluorescence resonance energy transfer (FRET) was used to measure the beta cleavage and gamma cleavage of APP. A beta generation was confirmed by immunocytochemistry and multiphoton laser scanning microscopy. Cell viability was tested by MTT assay at different time points. RESULTS: (1) The double restriction endonuclease digestion and sequencing analysis confirmed the authenticity of the recombinant plasmids pcDNA3.0-CFP-54bp-YFP and pcDNA3.0-CFP-54bp-YFP-C99. (2) Blue and yellow fluorescences were detected in the transfected cells. (3) FRET occurred in pcDNA3.0-CFP-54bp-YFP-transfected cells but not in pcDNA3.0-CFP-54bp-YFP-C99-transfected cells. (4) A beta was produced in the pcDNA3.0-CFP-54bp-YFP-C99 transfected cells. (5) A beta-deposition was widespread in the cell. (6) Cell viability decreased along with the intracellular A beta deposition. CONCLUSION: C99 is important for the APP beta cleavage. A beta may be generated and deposited in cells at the early stage of Alzheimeros disease. Intracellular A beta accumulation brings deleterious effects on cells.