Effect and molecular mechanism of mir-146a on proliferation of lung cancer cells by targeting and regulating MIF gene

Objective: To discuss the effect and molecular mechanism of mi R-146 a on the proliferation of lung cancer cells by targeting and regulating the macrophage migration inhibitory factor(MIF) gene. Methods: RT-PCR was employed to detect expression of mi R-146a; immunohistochemistry was used to detect the expression of MIF. The luciferase reporter gene technique was adopted to verify that MIF was the specific reverse target gene of mi R-146 a and the liposome LipofectamineTM2000 was employed to transfer the modeled mi R-146 a mimics, and mi R-146 a negative control(NC) in NSCLC cells to detect the expression of MIF m RNA and protein. MTT assay was used to detect cell viability, cloning technique to detect cell proliferation ability, Annexin V-PI to detect cell apoptosis, UV spectrophotometry to detect viability of cysteinyl aspartate specific proteinase 3(Caspase 3), and western blot to detect expression of nuclear factor-κB(NF-κB) in cells. Results: The expression of mi R-146 a in NSCLC lung tissues was lower than that in the normal lung tissues besides the lung cancer; while the expression of mi R-146 a in NSCLC cells was lower than that in normal human embryonic lung tissues. It was chosen as the subsequent cell line for its appropriate expression in A549. The expression of MIF protein in NSCLC lung tissues was higher than that in the normal lung tissues besides the lung cancer. The luciferase reporter gene proved that MIF was the reverse target gene of mi R-146 a. The mi R-146 a mimics were transfected into A549 cells through the liposome. Compared with NC group, the expression of MIF protein and m RNA was significantly decreased(P<0.01), with the decrease in the cell viability(P<0.01), the decrease in the number of clones(P<0.01), cell apoptosis(P<0.01), the increase in the activity of Caspase 3(P<0.01), and decrease in the phosphorylation of NF-κB p65(P<0.01). Conclusions: mi R-146 a has low expression in NSCLC tissues and cell lines, while MIF has the over expression in NSCLC tissues. The increased expression of mi R-146 a can inhibit the expression of MIF via the gene targeting and thus inhibit the proliferation of A549 cells and induce the apoptosis of cancer cells, which may be realized through NF-κB signaling pathway.

ELECTRICAL PROPERTIES OF CONDUCTIVE POLYMER COMPOSITES PREPARED BY AN INNOVATIONAL METHOD

An innovational method that poly(styrene-co-maleic anhydride)(SMA),a compatibilizer of immiscible nylon6/polystyrene(PA6/PS) blends,was first reacted with carbon black(CB) and then blended with PA6/PS,has been employed to prepare the PA6/PS/(SMA-CB) composites of which CB localized at the interface.In PA6/PS/CB blends,CB was found to preferentially localize in the PA6 phase.However,in the PA6/PS/(SMA-CB) blends,it was found that CB particles can be induced by SMA to localize at the interface.The electrical porperties of PA6/PS/(SMA-CB) composites were investigated.The results showed that the composites exhibited distinct triple percolation behavior,i.e.the percolation is governed by the percolation of CB in SMA phase,the continuity of SMA-CB at the interface and the continuity of PA6/PS interface.The percolation threshold of PA6/PS/(SMA-CB) was only 0.15 wt%,which is much lower than that of PA6/PS/CB.Moreover,the PTC(positive temperature coefficient) intensity of PA6/PS/(SMA-CB) composites was stronger than that of PA6/PS/CB and the negative temperature coefficient(NTC) effect was eliminated.The electrical properties of PA6/PS/(SMA-CB) were explained in terms of its special interface morphology:SMA and CB localize at interphase to form the conductive pathways.

Direct Comparison of Crystal Nucleation Activity of PCL on Patterned Substrates

A sample containing different regions with poly(ε-caprolactone)(PCL), oriented polyethylene (PE), and oriented isotactic polypropylene (iPP) films in contact with glass slide has been prepared to be observed in the same view field in an optical microscope and the crystallization of PCL in different regions during cooling from 80 °C down to room temperature at a rate of 1 °C·min^-1 was studied. The results showed that the crystallization of PCL started first at the PE surface and then at the iPP surface, while its bulk crystallization occured much later. This indicates that though both PE and iPP are active in nucleating PCL, the nucleation ability of PE is stronger than that of iPP. This was due to a better lattice matching between PCL and PE than that between PCL and iPP. Moreover, since lattice matching existed between every (hk0) lattice planes of both PCL and PE but only between the (100)PCL and (010)iPP lattice planes, the uniaxial orientation feature of the used PE and iPP films resulted in the existence of much more active nucleation sites of PCL on PE than on iPP. This led to the fact that the nucleation density of PCL at PE surface was so high that the crystallization of PCL at PE surface took place in a way like the film developing process with PCL microcrystallites happened everywhere with crystallization proceeding simultaneously. On the other hand, even though iPP also enhanced the nucleation density of PCL evidently, the crystallization of PCL at iPP surface included still a nucleation and crystal growth processes similar to that of its bulk crystallization.