Overexpression of proteasome 26S subunit non-ATPase 6 protein and its clinicopathological significance in intrahepatic cholangiocarcinoma

BACKGROUND Currently,intrahepatic cholangiocarcinoma(ICC)poses a continuing,significant health challenge,but the relationship has yet to be established between ICC and the proteasome 26S subunit non-ATPase 6(PSMD6).AIM To investigate the protein expression and clinicopathological significance of PSMD6 in ICC.METHODS The potential impact of the PSMD6 gene on the growth of ICC cell lines was analyzed using clustered regularly interspaced short palindromic repeat knockout screening technology.Forty-two paired specimens of ICC and adjacent noncancerous tissues were collected.PSMD6 protein expression was determined by immunohistochemistry.Receiver operating characteristic curve analysis was performed to validate PSMD6 expression level,and its association with ICC patients’various clinicopathological characteristics was investigated.RESULTS The PSMD6 gene was found to be essential for the growth of ICC cell lines.PSMD6 protein was significantly overexpressed in ICC tissues(P<0.001),but showed no significant association with patient age,gender,pathological grade,or tumor-node-metastasis stage(P>0.05).CONCLUSION PSMD6 can promote the growth of ICC cells,thus playing a pro-oncogenic role.

CONTRIBUTION OF CHOLESTEROL MOIETIES ATTACHED ON MPEG-b-PCL-b-PLL TO THE CELL UPTAKE, ENDOSOMAL ESCAPE AND GENE KNOCKDOWN OF THE MICELLEPLEXES OF siRNA

To further enhance the transfection efficiency of a micelleplex system based on monomethoxy poly（ethylene glycol）-block-poly（e-caprolactone）-block-poly（L-lysine） （MPEG-b-PCL-b-PLL）, cholesterol （Chol） moieties are attached to the e-termini of PLL segments to obtain MPEG-b-PCL-b-PLL/Chol. The structure and morphology of the copolymer are studied by IH-NMR, TEM and DLS （dynamic light scattering）. The cytotoxicity, cell uptake, endosomal release and mRNA knockdown are studied by MTT （3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide） assay, flow cytometry, CLSM （confocal laser scanning microscopy） and RT-PCR （real-time polymerase chain reaction）. The results show that compared to their precursor MPEG-b-PCL-b-PLL, the cholesterol-grafted copolymer shows significantly lower toxicity, more rapid cellular endocytosis and endosome escape, and consequently displays enhanced siRNA transfection efficiency even at a lower N/P ratio. These improvements are ascribed to enhanced interaction of the cholesterol moieties with both cellular membrane and endosomal membrane. Moreover, effect of the PLL block length is examined. The final conclusion is that long enough PLL segments and incorporation of proper fraction of cholesterol onto the PLL segments benefit the enhancement of siRNA transfection efficiency.