RESUMEN
Understanding the influence of surfactants on the assembly of peptides has a considerable practical motivation. In this paper, we systematically study the anionic surfactant-assisted assembly of diphenylalanine (FF). FF forms broom-like structures in a concentration of sodium cholate (NaC) around the CMC, and assembles into linear and unidirectional rods in the presence of low and high surfactant concentrations. FF's improved hydrogen bonding and controlled assembly rates are appropriate for other anionic surfactants. At this stage, the use of FF as the simplest protein consequence can be helpful in the investigation of further protein-surfactant interactions.
Asunto(s)
Cytisus , Surfactantes Pulmonares , Dipéptidos , Fenilalanina/química , Tensoactivos/químicaRESUMEN
The present study aimed to determine how the expression and function of HOTTIP modifies, and regulates the metabotropic glutamate receptor 1 (mGluR1) to affect human pancreatic cancer cell viability. HOTTIP expression was higher in human pancreatic cancer tissue compared with in para-carcinoma tissue. However, downregulation of HOTTIP expression was revealed to significantly reduce cell viability, induce apoptosis, promote caspase-3 and caspase-8 activities and increase Bax expression in pancreatic cancer cells. Additionally, downregulation of HOTTIP expression significantly suppressed mGluR1 and mitigated activation of the phosphoinositide 3-kinase (PI3K)/Akt/mechanistic target of rapamycin (mTOR) pathway in pancreatic cancer cells. To the best of our knowledge, the present study is the first to identify that the anticancer effect of HOTTIP against human pancreatic cancer functions the mGluR1 pathway.
RESUMEN
Aberrant activations of Hedegehog (Hh) signaling were found in hepatocellular carcinoma (HCC) and some other cancer types. However, the details have not been completely understood and the underlying mechanism remains unclear. Here we reported that miR-1249 transcription in HCC cells was regulated through direct binding to the conserved sequences in miR-1249 promoter region by Gli1, which functions as a transcription factor and is a component in the Hh signaling pathway. Interestingly, expression of tumor suppressor PTCH1, which is another component of the Hh signaling pathway, was inhibited by miR-1249 through targeting its 3'-untranslated region. Down-regulation of PTCH1 further enhanced the downstream effects mediated by Gli1. In consistent with these findings, miR-1249 expression level was correlated with degree of prognosis (p=0.005) in HCC patients. Taken together, our results suggested the existence of a positive feedback loop comprised of Gli1, miR-1249 and PTCH1. During the process of HCC progression, this positive feedback loop could be continuously activated to enhance tumor cell growth, migration and invasion.
Asunto(s)
Carcinoma Hepatocelular/genética , Regulación Neoplásica de la Expresión Génica/genética , Neoplasias Hepáticas/genética , MicroARNs/genética , Transducción de Señal/genética , Carcinoma Hepatocelular/metabolismo , Regulación hacia Abajo/efectos de los fármacos , Regulación hacia Abajo/genética , Perfilación de la Expresión Génica , Humanos , Neoplasias Hepáticas/metabolismo , MicroARNs/metabolismo , MicroARNs/farmacología , Receptor Patched-1/antagonistas & inhibidores , Receptor Patched-1/genética , Receptor Patched-1/metabolismo , Células Tumorales CultivadasRESUMEN
The preparation and stability of oil-in-water emulsions stabilized by hydrophobically modified hydroxyethyl cellulose (HMHEC) were investigated. The rheological measurements of aqueous HMHEC were studied. It was found that HMHEC showed much better thickening ability than the parent (HEC) from which it was derived, which is caused by the association of the hydrophobic alkyl chains, which are absent in HEC. The oscillatory experimental results of the emulsions showed that at higher concentrations, HMHEC could form an elastic gel, which has good thixotropic properties. The stability and droplet size distribution were investigated by visual observation, photomicrograph and a laser-scattering particle size distribution analyzer. The adsorption of HMHEC at the oil-water interface and the surface of emulsion droplets due to the penetration of the alkyl chains in HMHEC into the oil phase were confirmed by visual observation, the interfacial tension method and an in situ environmental scanning electron microscope (ESEM). The stability of emulsions prepared using HMHEC is based on both an associative thickening mechanism caused by alkyl chains in HMHEC and the adsorption of HMHEC at the oil-water interface, which can form a solid film preventing coalescence of the droplets.
