Long non‐coding RNAs (lncRNAs) take various effects in cancer mostly through sponging with microRNAs (miRNAs). lncRNA NR2F1‐AS1 is found to promote tumour progression in hepatocellular carcinoma, endometrial cancer and thyroid cancer. However, the role of lncRNA NR2F1‐AS1 in breast cancer angiogenesis remains unknown. In this study, we found lncRNA NR2F1‐AS1 was positively related with CD31 and CD34 in breast cancer through Pearson's correlation analysis, while lncRNA NR2F1‐AS1 transfection promoted human umbilical vascular endothelial cell (HUVEC) tube formation. In breast cancer cells, lncRNA NR2F1‐AS1 enhanced the HUVEC proliferation, tube formation and migration ability through tumour‐conditioned medium (TCM). In zebrafish model, lncRNA NR2F1‐AS1 increased the breast cancer cell‐related neo‐vasculature and subsequently promoted the breast cancer cell metastasis. In mouse model, lncRNA NR2F1‐AS1 promoted the tumour vessel formation, increased the micro vessel density (MVD) and then induced the growth of primary tumour. Mechanically, lncRNA NR2F1‐AS1 increased insulin‐like growth factor‐1 (IGF‐1) expression through sponging miRNA‐338‐3p in breast cancer cells and then activated the receptor of IGF‐1 (IGF‐1R) and extracellular signal‐regulated kinase (ERK) pathway in HUVECs. These results indicated that lncRNA NR2F1‐AS1 could promote breast cancer angiogenesis through IGF‐1/IGF‐1R/ERK pathway.
Oxidative damage is a key factor for the pathogenesis of age‑related macular degeneration (AMD), therefore, anti-oxidative stress is a valuable method for the prevention or treatment of AMD. The aim of the present study was to reveal the protective mechanism of lutein on retinal pigment epithelium (RPE) cells subjected to oxidative stress. Acute retinal pigment epithelial 19 (ARPE‑19) cells were exposed to oxidative stress induced by H2O2 following lutein pretreatment. The activities of caspases, level of intracellular reactive oxygen species (ROS) and cell cycle were analyzed using flow cytometry. The expression levels of cell cycle regulatory proteins and inflammation‑associated genes were detected using western blot and reverse transcription‑polymerase chain reaction analyses, respectively. The data showed that oxidative stress reduced cell viability, and increased total apoptosis and ROS generation, however, lutein prevented cells from oxidative stress‑induced damage. In addition, oxidative damage triggered G2/M phase arrest of the ARPE‑19 cells, which was reversed by lutein in a concentration‑dependent manner, through the activation of cyclin‑dependent kinase 1 and cell division cycle 25C, and degradation of cyclin B1. These results demonstrated that lutein may be an effective antioxidant, which can be applied in the prevention of AMD, or other age-related diseases associated with oxidative damage.
Retinoblastoma (RB) is a highly aggressive paediatric ophthalmological malignancy that commonly affects the eyes of children under 5 years old and is responsible for 5% of blindness in children. 1,2 Retinoblastoma initiation occurs with exceptionally high efficiency in response to the loss of functional pRB protein, which is encoded by the RB1 gene. 3 Retinoblastoma is derived from the immature
PURPOSE. To investigate whether dexamethasone has an effect on functional expression of p-glycoprotein in cultured human RPE and, if so, whether this occurs through interaction with glucocorticoid receptor (GR) and pregnane X receptor (PXR).METHODS. The human RPE D407 was treated with increasing concentrations of dexamethasone and/or RU486 for various time periods up to 24 hours. Treated cells were collected for cell viability, expressions of p-glycoprotein and PXR, and rhodamine 123 accumulation assays. GR expression plasmid and rifampicin were chosen to investigate the relationship of GR/PXR activation and p-glycoprotein expression.RESULTS. Significant increases in p-glycoprotein, as indicated by mRNA and protein levels, as well as by functional activity, were induced within 12 hours of dexamethasone treatment, persisted as long as 24 hours, and were dose-dependent and attenuable with coculture of RU486. In parallel, a dosedependent upregulation of PXR was notable at both mRNA and protein levels by 24 hours of dexamethasone treatment, and was partially reversible with RU486 coculture. Additionally, transfection of GR expression plasmid increased the transitional expressions of PXR and p-glycoprotein in untreated cells, and enhanced PXR transcriptional expression in dexamethasone-treated cells. Further, PXR silencing inhibited the dexamethasone-induced p-glycoprotein alterations; however, rifampicin had no apparent effects on the dexamethasoneinduced p-glycoprotein alterations. CONCLUSIONS.Our results suggest for the first time that expression and activation of p-glycoprotein involve GR and PXR in human RPE. (Invest Ophthalmol Vis Sci. 2012;53:3508-3515) DOI:10.1167/iovs.11-9337 R PE plays an essential role in protecting neural tissues from toxic materials and in maintaining vision and neural function in the retina by forming the outer blood-retinal barrier (BRB). It has been demonstrated that the outer BRB not only regulates the ionic environment of the subretinal space, secretes factors for structural integrity of the retina, phagocytizes shed outer segments of photoreceptors, and participates in the visual cycle, 1 but also limits vitreal penetration of drugs administered by the systemic and transscleral routes. 2-4 Efflux transport systems provide further barriers for the retina, by actively removing cytotoxic drugs and specific xenobiotic compounds from the retina and transferring them back into the systemic circulation.5,6 P-glycoprotein (P-gp), a 170-kDa protein encoded by the multiple drug resistance human MDR1 gene, is a member of the ABC superfamily of energy-dependent transport systems.7 As a well-characterized efflux transporter, P-gp is strongly expressed by retinal vascular endothelial cells 8 and has recently been identified in human RPE. 9 P-gp displays broad specificity, accepting many structurally, functionally, and mechanistically unrelated compounds, 10 and its role in limiting drug penetration across biological barriers is well established. Although efflux pumps such as P-gp are best known ...
Transgelin 2 (TAGLN2) is a cytoskeletal protein of the calponin family. Abnormal expression of TAGLN2 was observed in various types of cancer. Our previous study reported that TAGLN2 expression was reduced in lymph node-positive breast cancer patients; however, the role of TAGLN2 in breast cancer metastasis remains unknown. In the present study, the role of TAGLN2 in breast cancer metastasis was investigated in vitro and in vivo via Transwell migration, luciferase and flow cytometry assays, and a mouse xenograft model. Proteins interacting with TAGLN2 were identified via co-immunoprecipitation assays and liquid chromatography/mass spectrometry, and the signaling pathway associated with the effects of TAGLN2 was investigated. Additionally, western blotting and reverse transcription-quantitative polymerase chain reaction were performed to further explore the potential pathway in which TAGLN2 may be involved and the mechanism underlying its effects in breast cancer metastasis. The present study reported that TAGLN2 expression was increased by 11.4-fold in patients without distant metastasis compared with those positive for distant metastasis. Knockdown of TAGLN2 resulted in increased cell migration in vitro and promoted lung metastasis in vivo. Additionally, overexpression of TAGLN2 suppressed lung metastasis in a mouse model. Peroxiredoxin 1 (PRDX1), an important reactive oxygen species (ROS) regulator, was revealed to interact with TAGLN2. In addition, mitochondrial redistribution and PRDX1 downregulation were reported following TAGLN2 silencing, which promoted ROS production and nuclear factor (NF)-κB activation in breast cancer cells. This induced the expression of metastasis-associated genes, including C-X-C chemokine receptor 4, matrix metalloproteinase (MMP)1 and MMP2. The present study proposed TAGLN2 to function as a tumor suppressor and that loss of TAGLN2 may promote the metastasis of breast cancer by activating the ROS/NF-κB signaling pathway.
The Notch signaling is an evolutionarily conserved cell-cell communication pathway that plays critical roles in the proliferation, survival, apoptosis, and fate determination of mammalian cells. Retinal pigment epithelial (RPE) cells are responsible for supporting the function of the neural retina and maintaining vision. This study investigated the function of Notch signaling in RPE cells. We found that the members of the Notch signaling pathway components were differentially expressed in RPE cells. Furthermore, blockage of Notch signaling inhibited the migration and proliferation of RPE cells and reduced the expression levels of certain Notch signaling target genes, including HES1, MYC, HEY2, and SOX9. Our data reveal a critical role of Notch signaling in RPE cells, suggesting that targeting Notch signaling may provide a novel approach for the treatment of ophthalmic diseases related to RPE cells.
Our results in this study also provide the insights to broaden the application of curcumin in research and probably clinics.
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