GLDC mitigated by miR-30e regulates cell proliferation and tumor immune infiltration in TNBC.

Background: TNBC, whose clinical prognosis is poorer than other subgroups of breast cancer, is a malignant tumor characterized by lack of estrogen receptors, progesterone hormone receptors, and HER2 overexpression. Due to the lack of specific targeted drugs, it is crucial to identify critical factors involved in regulating the progression of TNBC. Methods: We analyzed the expression profiles of TNBC in TCGA and the prognoses values of GLDC. Correlations of GLDC and tumor immune infiltration were also identified. CCK8 and BrdU incorporation assays were utilized to determine cell proliferation. The mRNA and protein levels were examined by using Real-time PCR and Western blot analysis. Results: In the present study, we analyzed the mRNA expression profiles of TNBC in TCGA and found that GLDC, a key enzyme in glycine cleavage system, was significantly up-regulated in TNBC tissues and higher expression of GLDC was correlated with a worse prognosis in TNBC. Moreover, the expression of GLDC was negatively correlated with macrophage and monocyte and positively correlated with activated CD4 T cell and type 2 T helper cell in TNBC. Overexpression of GLDC facilitated the proliferation of TNBC cells, whereas GLDC knockdown had the opposite effects. Additionally, miR-30e acts as a functional upstream regulator of GLDC and the inhibitory effects of miR-30e on cell proliferation were mitigated by the reintroduction of GLDC. Conclusions: These results imply that miR-30e-depressed GLDC acts as a tumor suppressive pathway in TNBC and provides potential targets for the treatment of TNBC.

Nest site selection for five common birds and their coexistence in an urban habitat.

Many species of birds gradually adapt to urbanization and colonize cities successfully. However, their nest site selection and competitive relationship in an urban community remain little known. Understanding the impact of urbanization on birds and the competitive relationship has important implications for the conservation and management of wildlife in urban ecosystems. Here, we undertook a systematic study to quantify nests in all species of birds in an urbanizing area of Nanchang, China. A total of 363 nests were detected in surveys including 340 nests of 16 bird species and 23 unidentified species nests. We mainly analyzed 5 dominant breeding birds with a sample size of >10 during the two breeding seasons (From April to July in 2016 and 2017), which included the light-vented bulbul, Chinese blackbird, scaly-breasted munia, spotted dove and grey-capped greenfinch. Most birds (93.66%) nested in the tree of artificial green belts, which seems to be the best breeding habitat for urban birds. Our results suggested that birds' breeding success relies on the trade-off between the benefit and the expense of specific stresses from habitats. The nest site selection of birds is also affected by the life habit of urban predators. Furthermore, competition among species can influence their distributions and utilization of environmental resources when birds nest in cities. We confirmed that the niche differentiation of five bird species in an urban environment makes them coexist successfully by utilizing various resources.