ABSTRACT
A number of microRNAs (miRNAs), including miR-200 family, are aberrantly expressed in endometriosis and endometrial cancer. Here we assessed the expression and functional aspects of miR-200c in endometrial tissues (N = 52) from normal endometrial biopsies (N = 15), endometrial tissues including those exposed to hormonal therapies (N = 20), and grade I-III endometrial cancer (N = 17). miR-200c expression was elevated in normal endometrial biopsies from mid- and late-luteal phase, and in endometrial tumors as compared to endometrial tissues from peri- and postmenopausal period (P < .05) and its pattern of temporal expression displayed an inverse relationship with the expression of ZEBs. The expression of E-cadherin (CDH1) varied, but expressed at low levels, specifically in endometrial tissues and endometrial tumors. The endometrial expression of ZEBs and CDH1 in patients who were exposed to Depo-Provera and gonadotropin-releasing hormone agonist GnRHa displayed a trend toward lower expression as compared to proliferative phase; however, treatment of Ishikawa cells with 17ß-estradiol, progesterone, and medroxy progesterone acetate had modest effects on the expression of miR-200c and ZEBs without affecting CDH1 expression. Gain of function of miR-200c in Ishikawa cells repressed ZEBs, as well as VEGFA, FLT1, IKKß, and KLF9 expression at transcriptional and translational levels through direct interaction with their respective 3'untranslated regions and increased the rate of their proliferation. These results indicated that endometrial miR-200c expression undergoes dynamic changes during transition from normal into cancerous states; possibly influenced by hormonal milieu and by targeting the expression of specific genes with key regulatory functions in cellular transformation, inflammation, and angiogenesis may influence these events during normal and disease progression.
Subject(s)
Endometrial Neoplasms/genetics , Endometrium/metabolism , Homeodomain Proteins/genetics , MicroRNAs/genetics , Repressor Proteins/genetics , Transcription Factors/genetics , Adult , Aged , Aged, 80 and over , Cell Transformation, Neoplastic/genetics , Endometrium/chemistry , Estradiol/pharmacology , Extracellular Matrix Proteins/genetics , Female , Gene Expression Regulation, Neoplastic/drug effects , Humans , I-kappa B Kinase/genetics , Kruppel-Like Transcription Factors/genetics , Middle Aged , Progesterone/pharmacology , Real-Time Polymerase Chain Reaction , Transfection , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor Receptor-1/genetics , Zinc Finger E-box Binding Homeobox 2 , Zinc Finger E-box-Binding Homeobox 1ABSTRACT
Because the rate of a diffusional process such as protein folding is controlled by friction encountered along the reaction pathway, the speed of folding is readily tunable through adjustment of solvent viscosity. The precise relationship between solvent viscosity and the rate of diffusion is complex and even conformation-dependent, however, because both solvent friction and protein internal friction contribute to the total reaction friction. The heterogeneity of the reaction friction along the folding pathway may have subtle consequences. For proteins that fold on a multidimensional free-energy surface, an increase in solvent friction may drive a qualitative change in folding trajectory. Our time-resolved experiments on the rapidly and heterogeneously folding beta-hairpin TZ2 show a shift in the folding pathway as viscosity increases, even though the energetics of folding is unaltered. We also observe a nonlinear or saturating behavior of the folding relaxation time with rising solvent viscosity, potentially an experimental signature of the shifting pathway for unfolding. Our results show that manipulations of solvent viscosity in folding experiments and simulations may have subtle and unexpected consequences on the folding dynamics being studied.
