RESUMO
Acute cerebral infarction(ACI)has the characteristics of onset nasty and high mortality,and thus the rapid determination of the occurrence and development of ACI plays a key role in the diagnosis,treatment and prognosis of ACI patients.It has shown that the serum level of human haptoglobin(Hp)is related to ACI.In this study,surface enhanced Raman scattering(SERS)combined with immune recognition was applied to establish a quantitative analysis method for serum Hp.Firstly,the SERS substrate of silver nanoparticles was prepared on silicon wafer,and 4-mercaptobenzoic Acid(MBA)was used as a Raman probe by forming Ag—S bond and connecting it on the surface of nanoparticles.The carboxyl group of MBA was linked to amino group of self-made high-affinity antibody through forming CO—NH structure thus forming a SERS self-assembled chip of Hp(Ag/MBA/anti-Hp).Hp in serum could be specifically captured by antibodies on SERS substrate,which caused the shift of SERS characteristic peak of MBA.The results showed that there was a good linear relationship between the logarithm of Hp concentration and the SERS characteristic peak shift of MBA.The detection range was 1-1000 ng/mL(R2=0.988).The Hp concentrations in serum of 90 ACI patients were determined by this method,and the results were consistent with those of ELISA method,which proved the practicability and accuracy of this method.This method was highly specific,simple and convenient,which could realize the specific recognition and quantitative analysis of serum Hp,so as to be an effective means for clinical detection of serum Hp,thus providing a reference for the treatment and prognosis of ACI.
RESUMO
<p><b>BACKGROUND</b>MicroRNAs (miRNAs) function as essential posttranscriptional modulators of gene expression, and are involved in a wide range of physiologic and pathologic states, including cancer. Numerous miRNAs are deregulated in hepatocellular carcinoma (HCC). This study aimed to investigate the role of miR-27a in the development of HCC.</p><p><b>METHODS</b>The expression of MiR-27a was measured by quantitative real-time polymerase chain reaction (qRT-PCR). 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide was used to examine changes in the viability of HepG2, Bel-7402, Bel-7404 hepatoma cell lines associated with up-regulation or down-regulation of miR-27a. A dual-luciferase activity assay was used to verify a target gene of miR-27a. Immunohistochemistry, qRT-PCR, Western blotting analysis, and cell cycle and apoptosis flow cytometric assays were used to elucidate the mechanism by which miR-27a modulates liver cancer cell proliferation.</p><p><b>RESULTS</b>The expression of miR-27a was significantly increased in HCC tissues and HepG2, Bel-7402, Bel-7404 hepatoma cell lines (P < 0.05). We also found that the down-regulation of miR-27a in HepG2 cells dramatically inhibited proliferation, blocked the G1 to S cell cycle transition and induced apoptosis (P < 0.05). In addition, miR-27a directly targeted the 3'- untranslated region of peroxisome proliferator-activated receptor γ (PPAR-γ), and ectopic miR-27a expression suppressed PPAR-γ expression on the mRNA and protein levels. The rosiglitazone-induced overexpression of PPAR-γ attenuated the effect of miR-27a in HCC cells.</p><p><b>CONCLUSIONS</b>Our findings suggested that miRNA-27a promoted HCC cell proliferation by regulating PPAR-γ expression. MiR-27a may provide a potential therapeutic strategy for HCC treatment.</p>