Objective To study the effects of apoptosis of the tumor cells in rabbit liver VX2 carcinoma after treatment by radiofrequency ablation(RFA) combined with trans arterial chemoembolization(TACE) and high‐frequency hyperthermia(HFH) . Methods Rabbit liver VX2 carcinoma model was established .Rabbit liver VX2 tumor models were divided into the following group:group A ,RFA+ TACE;group B ,RFA + TACE + HFH ;group C ,RFA + HFH ;group D ,TACE+ HFH .The changes of serum ALT was detected to realize the safety of the treatment .Cell apoptosis were detected by DNA agarose gel electrophoresis and terminal deoxynucleotidyltransferase‐mediated Dutp nick end‐labeling(TUNEL) assay ;SP immunohistochemistry ,Western blot and Real‐time quantitative PCR(RT‐PCR) were used to detect Caspase‐3 protein and mRNA expression levels .Results The changes of serum ALT in group B was significantly higher .Compared with other groups ,the apoptosis index in group B was increased marked‐ly(P<0 .05) .Western blot and RT‐PCR Caspase‐3 protein and mRNA levels in group B were higher than the other groups(P<0 .05) .Conclusion RFA+ TACE+ HFH can effectively kill tumor cells and promote apoptosis of tumor cells ,but ,at the same time ,can damage liver function .

OBJECTIVETo study the changes in hypoxia-inducible factor (HIF1α, HIF2α) in the residual tumor cells in nude mice bearing hepatocellular carcinoma (HCC) following treatment with high-intensity focused ultrasound (HIFU).

METHODSThirty nude mice bearing human HCC received treatment with HIFU. At 1, 3, and 5 days and 1 and 2 weeks after the treatment, the mice were examined for pathological changes of the residual tumor with HE staining; SP immunohistochemistry, Western blotting and real-time quantitative PCR were used to detect the protein and mRNA expressions of HIF1α and HIF2α in the tumor.

RESULTSHE staining revealed the presence of residual tumor cells and large necrotic areas after the treatment. Immunohistochemistry showed a gradual increment of HIF1α protein and mRNA expressions after the treatment, reaching the peak level at 3 days (P<0.05) followed by progressive reduction at 5 days and 1 and 2 weeks. HIF2α expressions at either the protein or mRNA levels exhibited no significant changes within 3 days after the treatment (P>0.05) but increased significantly at 5 days and 1 and 2 weeks (P<0.05).

CONCLUSIONThe changes of HIF1α and HIF2α in the residual tumor after HIFU treatment in nude mice bearing HCC can be associated with tumor cell apoptosis and angiogenesis after the treatment.

Animals ; Carcinoma, Hepatocellular ; metabolism ; pathology ; therapy ; Hep G2 Cells ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; metabolism ; Liver Neoplasms ; metabolism ; pathology ; therapy ; Mice ; Neoplasm, Residual ; metabolism ; pathology ; Ultrasonic Therapy ; methods

Lysis is a common functional module in synthetic biology and is widely used in genetic circuit design. Lysis could be achieved by inducing expression of lysis cassettes originated from phages. However, detailed characterization of lysis cassettes hasn't been reported yet. Here, we first adopted arabinose- and rhamnose-inducible systems to develop inducible expression of five lysis cassettes (S₁₀₅, A52G, C51S S76C, LKD, LUZ) in Escherichia coli Top10. By measuring OD₆₀₀, we characterized the lysis behavior of strains harboring different lysis cassettes. These strains were harvested at different growth stages, induced with different concentrations of chemical inducers, or contained plasmids with different copy numbers. We found that although all five lysis cassettes could induce bacterial lysis in Top10, lysis behaviors differed a lot at various conditions. We further found that due to the difference in background expression levels between strain Top10 and Pseudomonas aeruginosa PAO1, it was hard to construct inducible lysis systems in strain PAO1. The lysis cassette controlled by rhamnose-inducible system was finally inserted into the chromosome of strain PAO1 to construct lysis strains after careful screen. The results indicated that LUZ and LKD were more effective in strain PAO1 than S₁₀₅, A52G and C51S S76C. At last, we constructed an engineered bacteria Q16 using an optogenetic module BphS and the lysis cassette LUZ. The engineered strain was capable of adhering to target surface and achieving light-induced lysis by tuning the strength of ribosome binding sites (RBSs), showing great potential in surface modification.
Rhamnose/pharmacology* ; Plasmids/genetics* ; Pseudomonas aeruginosa ; Escherichia coli/metabolism*