The epigallocatechin gallate derivative Y reverses drug resistance mediated by the ABCB1 transporter both and

Previously, we reported that Y, a new epigallocatechin gallate derivative, is efficacious in reversing doxorubicin (DOX)--mediated resistance in hepatocellular carcinoma BEL-7404/DOX cells. In this study, we evaluated the efficacy of Y in reversing drug resistance both and by determining its effect on the adenosine triphosphate-binding cassette protein B1 transporter (ABCB1 or P-glycoprotein, P-gp). Our results showed that Y significantly sensitized cells overexpressing the ABCB1 transporter to anticancer drugs that are ABCB1 substrates. Y significantly stimulated the adenosine triphosphatase activity of ABCB1. Furthermore, Y exhibited a higher docking score as compared with epigallocatechin gallate inside the transmembrane domain of ABCB1. In addition, in the nude mouse tumor xenograft model, Y (110 mg/kg, intragastric administration), in combination with doxorubicin (2 mg/kg, intraperitoneal injection), significantly inhibited the growth of BEL-7404/DOX cell xenograft tumors, compared to equivalent epigallocatechin gallate. In conclusion, Y significantly reversed ABCB1-mediated multidrug resistance and its mechanisms of action may result from its competitive inhibition of the ABCB1 drug efflux function.

The effect of different pore sized hydroxyapatite for promoting bone vascularization in tissue engineering / 重庆医学

Objective To investigate the effect of different pore sized hydroxyapatite for promoting bone vascularization in tissue engineering.Methods Male Wistar rats were randomly divided into three groups,named group A,B and C,which were im-planted hydroxyapatite bioceramics compositing 4 μg bone morphogenetic protein with different aperture of 200 -300,350 -450, 500-600 μm in the back subcutaneously.The size of each block was 5 mm×5 mm×1 mm in a weight about of 40.0 mg.After im-plantation,the animals were killed and the implants and the surrounding tissue were taken out at the first,second,third and forth week respectively.HE staining of histological analysis was used to detect the situation of local neovascularization.Results There was significant difference between second and third week in group A.Comparing the area of vascularization at different time points in group B and group C,there were significant difference in the comparison of intragroup (P <0.05 ).During the first week after surgery,there was only group C that had the area of vascularization.During the second and forth week after operation,the area of vascularization in group B and group C were significant higher than group A (P <0.05).The C group showed a great deal of new-born blood vessels and clear formation of bone trabeculae.Conclusion The hydroxyapatite bioceramics of 500-600 μm could better promote vascalarization of tissue engineering in bone.

Relationship of PLXNC1 (rs2272335) polymorphism with genetic susceptibility to primary liver cancer among family clusters in Guangxi and its expression / 中国肿瘤临床

Objective:To investigate the correlation between plexinC1 (PLXNC1) rs2272335 polymorphism and the family clus-tering genetic susceptibility to primary liver cancer (PLC) in Guangxi and the expression of PLXNC1. Methods:Genotype and alleles of rs2272335 were determined in 20 liver cancer family groups (79 cases) and 10 healthy normal control groups (40 cases) in Fusui County through Time of Flight Mass Spectrometer. Immunohistochemistry detected the PLEXNC1 protein expression. Results:For the alleles of PLXNC1 (rs2272335) site, the risk of hepatocellular carcinoma (HCC) for individuals with [C] allele was 4.16-fold (95%CI=0.37-47.3, P=0.032) compared with that for individuals with [T] allele among the members of the healthy normal control group. The fre-quencies of the [C] and [T] alleles were similar in the HCC patients and the core individuals of liver cancer families (P>0.05). For the genotype of the PLXNC1 (rs2272335) site, the differences in frequencies of TT, TC, and CC genotypes were not statistically significant among the PLC patients and the core individuals of the liver cancer families and normal controls. The PLXNC1 protein expression in HCC (3.12±1.12) was higher than in hepatocellular paracancerous tissues (1.54±0.67) and in benign hepatocellular lesions (1.23±0.87) (P<0.05). Conclusion:The [C] allele of PLXNC1 (rs2272335) site might be the risk gene for the occurrence of PLC family clustering in Guangxi. PLXNC1 protein overexpression was closely correlated with PLC oncogenesis.

Blade differentiation and plantlet regeneration of Gynostemma pentaphyllum / 中草药

Objective To construct a stably-performing and high-efficiency regeneration system of Gynostemma pentaphyllum and lay a foundation for the gene transformation of it.Methods The blades of five-leaf G.pentaphyllum were used as the explants and cultured in MS media with different portions of hormone to induce fascicled-bud,root and plantlet regeneration.Results The medium suitable for inducing the blade differentiation of G.pentaphyllum was MS+6-BA 1.0 mg/L and for the frequency of blade differentiation could reach 40%.The cultural medium MS+6-BA 1.0 mg/L was suitable for the sub-multiplication of fascicled-bud and the medium 1/2 MS for root inducement and the plantlet regeneration.Conclusion A stably-performing acceptor system of the direct differentiation for Agrobacterium tumefaciens mediated gene transformation of G.pentaphyllum blades is constructed.