A study on the inhibition of VEGF expression in salivary gland adenoid cystic carcinoma cells via iNOS gene RNAi in vitro

In this study, we aimed to explore the effect of inducible nitric oxide synthase (iNOS) on vascular endothelial growth factor (VEGF) expression in salivary gland adenoid cystic carcinoma (SACC). Using RNAi, we transfected chemically synthesised iNOS siRNA into ACC‐M cells (a highly metastatic adenoid cystic carcinoma cell line) and detected the change in the gene and protein expression levels of iNOS and VEGF by qRT‐PCR and Western blotting. A transwell invasiveness assay was used to examine the changes in invasive ability of ACC‐M cells. Cell growth was determined using a CCK‐8 assay. Apoptosis and cell‐cycle phases were detected by flow cytometry. We found that silencing iNOS down‐regulated the expression of VEGF and then inhibited cell growth and invasiveness of SACC cells, while it increased apoptosis. Therefore, we concluded that iNOS can regulate VEGF expression and iNOS may be a therapeutic target.     

Modulation of in vitro eosinophil progenitors by hydrocortisone: role of accessory cells and interleukins

The growth of human eosinophil progenitors (CFU-Eo) and the modulation of growth by hydrocortisone were studied as functions of the presence of lymphocytes and monocytes in marrow cells under study; and the source of colony-stimulating factors, specifically, media conditioned by macrophage-like cell line, GCT; phytohemagglutinin-stimulated mononuclear cells (PHA-LCM); or the T cell line, MO. CFU-Eo growth was greatest in marrow containing accessory cells as compared to marrow depleted of accessory cells; and in marrow treated with phytohemagglutinin-stimulated leukocyte conditioned media (PHA-LCM) or MO (T cell line)-conditioned medium (MO-CM) as compared with GCT cell- conditioned medium (GCT-CM). Hydrocortisone reproducibly inhibited eosinophil progenitor growth in unfractionated marrow stimulated by GCT- CM. This effect was abrogated by admixing irradiated mononuclear cells or T lymphocytes with the target marrow or by adding interleukin 1 or interleukin 2 (IL-1, IL-2). Inhibition by hydrocortisone did not occur when monocyte and T lymphocyte depleted marrow was studied. Unlike GCT- CM, MO-CM and PHA-LCM stimulated equal proportions of eosinophil progenitors in nondepleted and accessory cell-depleted marrow and demonstrated less hydrocortisone inhibition. However, both GCT-CM and PHA-LCM produced in the presence of hydrocortisone stimulated significantly fewer CFU-Eos in both unfractionated and accessory cell- depleted marrow target populations. These results indicate that the growth of CFU-Eo and inhibition of growth by hydrocortisone is a direct function of a monocyte-T cell interaction and probably is mediated through effects on the production/release of eosinophil colony stimulating factor (Eo-CSF).