g. addition of corticosterone to drinking water, transfer to a cold room at 4°C, subcutaneously administration with NE or β2-AR agonists, restraint procedure using open-ended Plexiglas cylindrical restrainers, social defeat, social isolation, unpredictable chronic mild stress, repeated social defeat, subcutaneous microosmotic pumps containing NE [12, Acalabrutinib in vivo 43–49]. However, some of stress models aforementioned have limitations more or less and thus induce unpredictable impacts on tests in vivo. For addition of corticosterone to drinking water, this test might not control the volume of water drunk by animals and thus the reliable uptake of corticosterone
can not be evaluated especially when uptake of water was interrupted by the disorders in animals such as a heavy tumor burden . buy 5-Fluoracil For the restraint test, it was found in our laboratory that mice would adapt the open-ended Plexiglas cylindrical restrainers in the later stage. So the restraint test might not sustain enough stress if the observation in a test in vivo should be kept for a long time . Seeing
that microosmotic pumps (1004 type) are of the ability of pumping drugs contained incessantly for up to 4 weeks and exhibit reliable effects in mouse models, the pumps were taken into account in our research to deal with the short half life period of NE. It is well known that in clinic patients are under chronic stress after diagnosed Phenylethanolamine N-methyltransferase with cancer prior to treatment. Thereby, in order to mimic patients in clinic as possible, sunitinib was administrated 30 minutes following NE in tests in vitro, and treatment with sunitinib was started 1 day after the implantation of pumps containing NE in tests in vivo. Tumor neovascularization or angiogenesis is closely related with proangiogenic factors such as VEGF, IL-8, IL-6, TGF and TNF released
by tumor cells and immune cells. In analogy to tumors cells, lymphocytes and macrophages in the tumor microenviroment also express β-ARs triggered by NE with the following increased levels of VEGF, IL-8, and IL-6 [50–53]. The NE-induced up-regulation of VEGF, IL-8, and IL-6 protein levels was found in a number of human cancer cell lines such as colon cancer, nasopharyngeal cancer, ovarian cancer, prostate cancer and melanoma [7, 8, 13, 17, 18]. This effect of NE was identified in murine melanoma B16F1 cells and human lung adenocarcinoma A549 cells in our study. In addition, this phenomenon was also observed in murine colon cancer CT26 cells and some human cancer cells (e.g., nasopharyngeal cancer HNE1 & CNE2 cells, breast cancer MDA-MB-231 & MDA-MB-468 cells and colon cancer HT-29 & SW480 cells) in other studies in our laboratory (unpublished date not shown). However, to our knowledge, nothing is known of the influence of NE in cancer cells treated with sunitinib in vitro.